If you’re prone to angry political opinions, you might want to be careful what you post about the Republican Convention in Cleveland this week — according to The Intercept, federal authorities are monitoring activists on Facebook and looking for signs of “violent anarchist extremist activity.”

The Intercept obtained a document earlier this month that purports to be a “Joint Threat Assessment” between the Department of Homeland Security, the Secret Service and the FBI. The document specifically calls out a “known anarchist extremist” group in Cleveland called Resist the Cleveland RNC and includes a link to the group’s Facebook page. However, the page mostly contains harmless resources and tips for activists traveling to Cleveland. Still, one of the administrators for the page claims she was visited by an FBI agent and a local police officer on the day after the Fourth of July, and was told she was a “person of interest.”

It makes sense that the government would be on high alert for the convention, especially given the wave of violence both in the U.S. and around the world in recent weeks. Experts warn that all Facebook users — particularly those in Cleveland or traveling to the convention — should be careful what they say on the site when it comes to hot-button issues.

“If you’re posting something on Facebook publicly, everyone can access it, including the government,” ACLU spokesperson Gary Daniels said. “People would have to be awfully naive to think that these things aren’t being monitored for people coming to Cleveland for the RNC.”