OSINT for Event Monitoring - Before, During, and After
- Kathryn Caudrelier & Amanda Schein
- May 14
- 6 min read
Updated: May 16
Event monitoring is the active observation and analysis of information surrounding major public gatherings — before, during, and after they take place. It’s a critical component of any security strategy, helping decision-makers identify risks early, respond to emerging threats, and maintain public safety and operational continuity.
Open-source intelligence (OSINT) has become an essential capability for security teams, law enforcement agencies and intelligence services involved in monitoring major events. In this blog, we explore how OSINT is shaping how large-scale events are monitored — providing real-time information, early warning indicators and greater visibility across both physical and digital domains. We’ll also share five of our favourite free tools to support teams across all stages of an event.
High-Profile Events Under Scrutiny
Event monitoring often brings to mind high-level meetings of international organisations or multilateral forums — such as the upcoming NATO Summit in the Netherlands — and for good reason. These events attract world leaders, diplomatic entourages, issue-motivated groups, and global media scrutiny, making them high-value targets for disruption, misinformation, and both physical and cyber threats.
But the need for event monitoring goes well beyond diplomatic conferences. It’s just as critical for music festivals, major sporting matches, corporate events and legal large-scale protests or rallies in public spaces. Events like the 2021 Astroworld Festival crowd crush, the storming of the Euro 2020 Final at Wembley and the 2017 Manchester Arena bombing have highlighted the increasing complexity of modern security and safety responsibilities.
When large crowds gather and the world is watching, the risk surface expands — and so does the need for comprehensive situational awareness. In these high-pressure environments, security agencies, emergency services and event organisers rely on timely, accurate intelligence to make critical decisions. OSINT offers the visibility and context needed to allocate resources, mitigate threats, and safeguard both people and infrastructure in real time.
OSINT Across the Event Lifecycle
To better understand OSINT’s practical value, it helps to break down its role across each stage of an event. From uncovering early warning signs to managing live incidents and conducting post-event reviews, OSINT gives security teams the tools to stay proactive, responsive and informed.
Before the Event: Anticipating Risks
The pre-event phase is all about understanding and shaping the threat landscape. OSINT allows analysts to:
Review past events to identify potential threats, challenges and operational takeaways
Monitor social platforms for protest planning or logistical coordination
Track media narratives and political flashpoints likely to influence an event
Investigate mis- and disinformation or ‘fake news’ campaigns to anticipate who may be consuming — and potentially acting on — these narratives
Identify groups or individual influencers attempting to mobilise unrest
Map out infrastructure vulnerabilities, such as transport choke points or unregulated gathering zones
Keyword tracking, forum analysis and post geolocation offer a strategic advantage — especially when conducted weeks or months in advance of an event.
Look Back to Plan Ahead
Reviewing past events using open-source tools and techniques offers better understanding during the pre-event phase. For law enforcement and intelligence teams, it’s an opportunity to surface potential threats, anticipate operational challenges and identify what has — and hasn’t — worked before.
To illustrate, let’s consider the 2025 NATO Summit in the Netherlands. As preparations ramp up, security agencies will likely be reviewing open-source indicators from past events – particularly those with similar geopolitical relevance or local context – to anticipate public safety and security challenges. For example, the 2024 NATO Summit in Washington DC saw activist groups mobilize around a multiplicity of issues such as military spending, the war in the Ukraine, and calls for a ceasefire in Gaza. These themes may again drive protest activity this year.
OSINT can also reveal how such movements are organised and amplified online, offering visibility into patterns of mobilisation, messaging strategies and preferred platforms. Understanding the expected baseline of digital activity is essential, particularly for identifying the proliferation of mis- and dis-information that can distort narratives or inflame tensions.
In some cases, protest activity has drawn opportunistic interest from foreign state actors. As seen in the US, the Intelligence Community identified some foreign government actors have sought to take advantage of existing protests to encourage or financially support protestors. These actions, and others, such as the sowing of disinformation, are designed to disrupt democratic processes, including to deepen societal divisions and undermine trust in institutions.
In the Netherlands, past open-source monitoring has shown how activist groups have coordinated disruptive actions across multiple digital channels – from motorway blockages near The Hague to the shutdown of coal terminals in the Port of Amsterdam.
Collectively, these observations highlight the importance of understanding how events have unfolded in the past to inform how they might occur today, and to better prepare both proactive monitoring and coordinated response efforts. Early analysis of online ecosystems can offer critical indicators of protest intent, scale, and tactics, enabling informed and timely decisions to safeguard public safety during the Summit.
During the Event: Real-Time Awareness
Once the event begins, the intelligence challenge shifts to real-time monitoring.
OSINT can enable teams to:
Monitor social media for breaking incidents or eyewitness accounts
Verify images or videos using metadata and contextual clues
Geolocate reported activity to direct the deployment of physical resources
Spot and counter misinformation before it spreads
Track public sentiment and adjust messaging or responses accordingly
The speed and reach of open-source monitoring allows for faster, more agile decision-making than traditional intelligence pipelines alone.
Pro tip: Don’t skip the comments section
When it comes to gauging public sentiment ahead of a major event, the news article isn’t the only thing worth reading — the comments section can be just as revealing. Prior to and during an event, analysts can use reader comments on mainstream news sites to:
Identify hashtags and keywords worth monitoring
Gauge reactions across different communities or demographics
Spot usernames or accounts that may warrant further investigation
Discover links to other forums or social platforms where related discussions are unfolding
These insights add valuable context — and can lead to early warning indicators that might not surface through official reporting or headlines alone.
After the Event: Learning and Evolving
The intelligence value doesn’t end when the event wraps. OSINT continues to play a critical role in the post-event phase, helping teams consolidate insights and strengthen future responses. OSINT supports:
Narrative analysis – Identifying which stories and narratives gained traction online.
Threat attribution – Determining the actors behind key disruptions or digital interference.
Misinformation mapping – Tracing the spread of false or misleading information and the channels used to distribute it.
Security assessment – Evaluating what worked, what didn’t, and where operational improvements can be made.
This retrospective analysis is essential for refining strategies, reinforcing capability and building a stronger, more resilient event security framework.
OSINT Tools for Event Monitoring at Every Stage
Here are five of our favourite free tools for event monitoring. These tools support OSINT analysts and security teams across all event phases — from planning to post-event analysis.
What it does: Tracks mentions, hashtags and keywords across various social media platforms.
Why it’s useful: Valuable before an event for detecting mobilisation or narrative-building efforts, and during an event to monitor evolving public discourse or incident reports.
What it does: Shows the position of the sun at a given time and location.
Why it’s useful: Effective during and after an event for verifying the timing and location of images posted online using shadow analysis — especially useful when metadata is missing or manipulated.
What it does: Sends notifications when selected keywords appear in new content online.
Why it’s useful: Ideal before and during an event for tracking protest announcements, key figure mentions or sudden narrative shifts.
Fact checkers (e.g. Snopes / BBC Verify)
What they do: Fact-check and verify news stories, images, viral claims and social media content.
Why they’re useful: Crucial before, during and after an event to spot and debunk false narratives, disinformation campaigns or misleading viral content that could impact public safety or perception.
What it does: Provides archived versions of websites, even if content has been changed or deleted.
Why it’s useful: Useful before an event for researching issue-motivated groups or other threat actor messaging, and after an event to retrieve removed or altered material for incident investigation or review. It is also useful to keep our attribution levels low!
Final Thoughts: Get your OSINT event-ready
From summits and stadiums to protests and public gatherings, OSINT is reshaping how we understand modern event security. By providing early warnings, real-time situational awareness and post-event insight, OSINT gives decision-makers a powerful advantage in an increasingly volatile and interconnected world.
Whether you’re preparing for a major event or strengthening your everyday monitoring capabilities, we’re here to support your mission. At OSINT Combine, we specialise in building enduring OSINT capability in your organisation with our internationally trusted training and OSINT software, NexusXplore. If you’d like to see NexusXplore's event monitoring capabilities in action, request a demo today!
