In case it’s not clear or you don’t want to read the thread, the FBI submitted screenshots of 8chan threads to court, apparently not realizing that although it’s an anonymous message board, replying to your own comments will show a little (You) to mark them as such, as seen here:
The (You) is only visible to the poster. The ID number will also remain the same, so those with ID: 8f4812 are likely employed by the government in some form: