There's a quantitive difference between an FBI agent inviting an idiot to coffee, and fabricating a plot with him to blow up a post office, and an FBI agent getting in touch with an idiot who is plotting to blow up a post office, and offering to give him fake explosives.
The former might be entrapment. The latter is good policework.
http://jfk.hood.edu/Collection/Weisberg%20Subject%20Index%20...
The police would plant people in suspect groups who pressure the rest of the group to engage in terrorist activity.
This isn’t exclusive to 1970s USA. Similar things happened in mosques after 9/11 where Imans would know an FBI agent simply because he was the only extremist in the congregation.
And in the United Kingdom, there were long term plants in environmental organisations who engaged in ecoterrorism.
I do not recall any stories of the latter.. perhaps there is one or some - and perhaps things have occurred that saved the X Y or Z and we'll never know - and that's great.
However I think it's high time that people paid more attention to the details of these "be afraid / keep sending us budgets" stories and see that many are fabricated just to check off a PR box.
9 out of 10 sex trafficking headline stories are the same, and similar.
It's not just the top level of the DOJ - the local law agencies use the same playbook (especially vice squads) for the same reasons. imho.
The fact that there still exists, to some degree, a mechanism in the USA to challenge this in some cases is indeed something to celebrate, but the quite reasonable comparison is not just legitimate and appropriate but is a tool for trying to fix the injustice, not just retail (one victim at a time) but wholesale (change of law).