I suppose one could capsulate all government police agencies into one, as they all have their individual heavy handed historical offenses.
The ATF seems to lead the pack in civilian loss of life for the last 40 years.
The FBI historically are lawyers, and accountants, and have been responsible for the mischief that lawyers, and accountants specialize in stirring up.
They are "word twisters" and "red ink detectives", that look for gotchas, even if the gotchas are out of context.
They, over the last few years, have become "openly politically left leaning" using their legal, and accounting skills to destroy conservative opponents.
J Edgar Hoover kept files on both parties to secure his job, and they knew it, so the FBI has always operated under the moto of legal, and financial manipulation of people to control them.
Recently they have thrown the "threat of force" into their repertoire of intimidation towards political opposition.