If five locations get ghostbusters in a city, suddenly one person will remove it from four of those locations. They want to drive business to their own place. I have lots of examples.
Edit now that I'm not on my phone and can type quickly: @phishrace is right on. There's very little accountability. There are, though, some fingerprints. We have IP addresses and device info. It's actually kind of fun to do some sleuthing, to see that a person left super positive comments on some machines (such as noting that an issue has been fixed, which is indicative of an operator), and then five seconds later trashed another place and removed a bunch of machines.
There are also some proven instances of operators messing with it. Two examples: I created a region, and the administrator was an operator. I told him that I usually don't let ops be admins, because of the potential to manipulate the data in their favor. He promised he wouldn't. He lied! He intentionally left off a competitor's locations. When confronted, he admitted it, and resigned rather than add that competitor's locations. And then what followed was a crapload of tampering in that region (after I added the competitor's locations). The other example is similar. I created a region, not realizing that the admin was a local operator. He added only his own locations (and did a terrible job at it), and then went AWOL. He never added any of the ones that other people submitted. I deleted the region.
Operators are the only map users who have money in the game. And some of them believe that the site will drive business. They whitewash critical machine comments with "BRAND NEW LED, PLAYS GREAT YOU GOTTA CHECK IT OUT!!!" and some seem intent on trashing their competitors. Last weekend someone removed every machine from Ground Kontrol (on the map). We restored the data within a couple minutes, and then a couple hours later they did it again, but this time they replaced the machines with random ones. And it was the same IP/device that a few minutes before left super positive comments at another location across town. No evidence that an operator did this. But, my hunch said it was.
Thus, we need a user system. I like having zero users. But we need more control, apparently.
Basically operators, or someone affiliated to them, try to mess with the competition. All they really do is create a hassle for us. Ops are great... But some of them annoy me to no end.