I checked to see if the comment from a “protest movement who shall not be named “is still up. It is and there’s a response noting another anecdotal example

there are many more examples such as this. This morning on Democracy now for example:
democracynow.org
from democracy now:
“More details have come to light showing how the U.S. military infiltrated and spied on a community of antiwar activists in the state of Washington. Democracy Now! first broke this story in 2009 when it was revealed that an active member of Students for a Democratic Society and Port Militarization Resistance was actually an informant for the U.S. military. The man everyone knew as “John Jacob” was in fact John Towery, a member of the Force Protection Service at Fort Lewis. He also spied on the Industrial Workers of the World and Iraq Veterans Against the War. A newly made public email written by Towery reveals the Army informant was building a multi-agency spying apparatus. The email was sent from Towery using his military account to the FBI, as well as the police departments in Los Angeles, Portland, Eugene, Everett and Spokane. He wrote, “I thought it would be a good idea to develop a leftist/anarchist mini-group for intel sharing and distro.” Meanwhile, evidence has also emerged that the Army informant attempted to entrap at least one peace activist, Glenn Crespo, by attempting to persuade him to purchase guns and learn to shoot. We speak to Crespo and his attorney Larry Hildes, who represents all the activists in the case.”

So, yes. The government does infiltrate radical groups looking for plans for violence and terrorism. I’m not shocked.