I’m not a massive fan of personalized license plates, but even I feel a little bad for Joseph Tartaro, a security researcher who, at one point, had as much as $12,049 in traffic fines because of an ill-advised license plate choice. Wired reports that Tartaro registered the plate back in late 2016, and since paying a single ticket back at the beginning of 2018, he’s been plagued by citations that have nothing to do with him.

That’s because Tartaro chose the word “Null” for his plate, which, as anyone who knows anything about programming will tell you, is a word that’s like catnip for badly programmed computer systems. “Null” is a special text string used in programming to tell a system that a value is empty or undefined. You’ve probably seen it crop up occasionally in Excel if you ever make a formatting error, and it’s already wreaked havoc on the life of one Christopher Null, who has to live with the word as his surname.

At one point, Tartaro had as much as $12,049 in traffic fines

The problem started in early 2018 when Tartaro paid a $35 parking fine for a minor violation. Wired notes that doing this seemed to associate the “Null” database entry with Tartaro’s details, after which all hell broke loose. Pretty soon, whenever any traffic cop didn’t enter a license number when writing a ticket, it would automatically get assigned to Tartaro. The DMV would void these tickets when Tartaro made them aware, but there was nothing he could do to stop them from coming.

This isn’t the first time we’ve seen computer systems thrown into disarray when faced with a text string they’re not expecting. Back in April, the podcast Reply All did an entire episode on a Mazda 2016 sedan’s infotainment system, which would crash whenever it was asked to play the podcast 99% Invisible over Bluetooth. (I won’t spoil exactly what the bug was, though, since the episode is worth listening to in its entirety.)

While the Mazda’s bug just stops people from listening to certain podcasts, Tartaro’s issue is a little more serious. The Californian DMV won’t let him renew his license until he’s paid off all his fines, and he doesn’t want to pay anything because this will cause him to admit liability. Then, trying to change his plate could make it look like he’s trying to avoid his existing tickets, which could cause yet more problems.

So let Tartaro’s ticketing nightmare be a lesson to you: sometimes programming terms need to be kept to coding.