If there’s a pantheon for dark patterns (sometimes known as “ asshole design “), T-Mobile has earned a spot on it for this dreadful example of deceptive user experience . The company used fake ring tone noises to make customers think their calls were connecting–while in fact they were not.

Here’s how it worked. Whenever a phone couldn’t establish a connection with another phone, instead of remaining silent, the calling tone would start ringing in the caller’s ear. Logically, the person placing the call believes that the phone on the other side is actually ringing but nobody is picking up. Of course, the fact is that their call is not going through at all, and T-Mobile is using a fake ringtone to make it seem like it is. This is actually illegal, according to a January 2014 rule, and the stakes are higher than you might imagine. The FCC says that the practice can “cause rural businesses to lose revenue, impede medical professionals from reaching patients in rural areas, cut families off from their relatives, and create the potential for dangerous delays in public safety communications.”

If you think that’s not that bad, imagine this: You’re driving through the middle of nowhere in Midwest Square State, U.S.A. Your car breaks down, your A/C is nonfunctional in the hot summer weather, and you call road assistance. The phone rings and rings, but nobody picks up. You call again. And again. It seems that everyone at road assistance must be out partying, or they just hate you. By the 27th call, you’d probably be mad enough to break the phone–all without realizing that your those rings were pure fiction, and you needed to move to find a better signal. And what if someone with you was injured, or a more serious emergency took place?

T-Mobile admitted its deceptive scheme to the commission and received a $40 million fine. Given that the trick affected “hundreds of millions” of people in rural areas and perhaps billions of calls, the fine represents just a few cents per call. Even worse: Consumers will not see a cent for this deception that. According to Ars Technica, FCC Commissioner Mignon Clyburn–who just stepped down from her post–was deeply critical of the fine, calling it absurdly low. The compliance plan contained in the FCC ruling, she says, “does not contain any concessions that would explain such a massive discount.” With Trump-appointed Ajit Pai in charge of the FCC, the treatment of telecomm companies probably won’t change any time soon.