Just the most recent examples of how DMs are used to target activists: The Colorado Springs police department forcing Meta to hand over the private Facebook messages of a housing justice advocate and of the Chinook Center, a small progressive Colorado Springs organization: 

Colorado Public Radio
Colorado ACLU sues Colorado Springs Police Department and FBI over alleged unlawful privacy invasions of local activist
The lawsuit says detectives and undercover officers infiltrated activists at the Chinook Center to gather information with the intent to arrest mem...