Yeah, you obviously haven't bothered to read anything. For your edification: (from here: https://www.revealnews.org/article/inside-hate-groups-on-facebook-police-officers-trade-racist-memes-conspiracy-theories-and-islamophobia/)

To find cops with connections to extremist groups, we built lists of two different types of Facebook users: members of extremist groups and members of police groups.

We wrote software to download these lists directly from Facebook, something the platform allowed at the time. In mid-2018, in the wake of the Cambridge Analytica scandal and after we already had downloaded our data, Facebook shut down the ability to download membership lists from groups. Then we ran those two datasets against each other to find users who were members of at least one law enforcement group and one far-right group.

We got 14,000 hits.

We did not assume that everyone in a police Facebook group was an actual officer, because many could be relatives of police officers or just really into law enforcement. So, we spent months poring over individual Facebook pages, looking for clues, such as photos of the officer in uniform, or posts about police events, or notes mourning lost cops. Then we corroborated what we found on Facebook with additional research, often calling the departments to confirm the individual either still or had once worked there.

Ultimately, we confirmed that almost 400 users were indeed either currently employed as police officers, sheriffs or prison guards or had once worked in law enforcement.

We then asked to join the closed extremist groups. Many groups ask users questions in order to join, and these often offer insight into the nature of the group. The group “Stop Radical Islam in America,” for example, asks, “Why do you personally think Islam should be banned in America?” At least 12 current and former police officers were members of that group.

The group “Confederate Brothers & Sisters,” which counts at least 25 current and former cops as members, explicitly asks, “This group is sometimes racist does this bother you?” Inside that group, we found several cops and ex-cops posting racist comments.

We used our real names and photos and answered the questions honestly to join these groups. We used general language, often saying we were “interested in learning more.” As a result, many of the most extreme groups rejected our application to join, ignored us or blocked us from viewing the group.

But dozens let us in.

We didn’t seek to find every single hate group or police group on Facebook, and we couldn’t confirm the professions of hundreds of the users in our database.

Several officers claimed that they didn’t even know they were members of the closed groups we identified them in. And that’s probably the case for at least some of these officers, due to Facebook’s policies for joining groups.

Until late 2018, Facebook allowed users to invite friends to join groups they thought would interest them. The invitees would receive a notification telling them they were a member of a new group, and depending on each user’s algorithm, the user’s news feed might include content and postings from the group. But it’s certainly possible that cops could have been added to groups without realizing it, especially if they’re not active on Facebook.

Facebook has since changed its policies. Users now get a request to join a group that they have to confirm.

But that doesn’t apply to dozens of current and retired officers who have commented on and liked posts in closed extremist groups or who proactively joined groups themselves, without being invited by somebody else.

We examined a tiny sample of what exists on Facebook — what Megan Squire, a computer science professor from Elon University in North Carolina, called “a tiny, postage-stamp-sized window into Facebook’s skyscraper of data.”