Undercover cops and government agents and controversial sting operations were the focus of John Oliver’s deep dive on Sunday’s episode of “Last Week Tonight.”

Oliver examined how stings have become a major part of policing over the past four decades as he highlighted some of the “pretty shitty” tactics used to catch people and pointed to how some operations disproportionately target certain ethnic groups and people with learning disabilities.

But one example, in particular, drew his strongest reaction:

“In one case, [ATF] agents set up a fake smoke shop in Portland and paid a 19-year-old who was mentally disabled, and his friend, to promote their store by, and this is true, getting a large tattoo on their necks of the fake shop’s emblem, which was a giant squid smoking a joint, which is utterly despicable.”

Oliver slammed a judge for mildly saying it was “not a good idea.”

“Not a good idea? Look, there is a time to be polite, but finding out agents just used taxpayer money to tattoo a teen with mental disabilities is not it. In fact, I looked up that exact situation in Emily Post’s book of etiquette and her advice just says, ‘Fuck those fuckers sideways with a rusty fork.’ I didn’t say that. Emily Post did, so you know it’s official.”

Watch here: