Blame this.
Chameleon Sculpture-Pythons
So, do you know what happens when you activate a portable dimensional gate generator with a leaky containment matrix? That’s right: nothing, usually. Unless you have the bad luck to have a fuse blow while the gate is active, because you were an idiot who wasn’t doing all the other standard maintenance on your portable dimensional gate generator, too. It that happens, well, you get a semi-permanent untuned gate for about ten seconds or so. A loud, attractive untuned gate. Sometimes Things From Outside come to investigate.
The absolute heck of it is, Chameleon Sculpture Pythons (CSP) aren’t intrinsically awful. Sure, they have the ability to infiltrate themselves into stone and make it as stretchy as taffy; and, doubly sure, they invariably end up possessing statues or busts or whatnot. But they aren’t malicious about it. CSPs feed off of radiation that is plentiful in our particular dimension: they have no fear of, no dislike for, and barely any awareness of, humans; and like any number of non-sentient species, they much prefer retreat to attack, and doesn’t really know how to attack things in our plane of existence anyway. If you can get your head around watching one of them move, they might even make acceptable pets.
Except that most of humanity simply cannot process watching a CSP move. There’s just something in our psychological makeup that will not accept that a statue might really get infested with a benign, essentially harmless parasite that can then make that statue ooze around the room. If a human think that it’s a fake or gimmick, that’s one thing: wonderful thing that they’re doing with CGI and/or origami these days, huh? But show one of these things to a person and convince him that the CSP is real, and that person is likely to be halfway to a 72 involuntary observation period on the spot. Which is why the relevant authorities are so diligent about collecting them as soon as a CSP ‘appears’ on the scene.
Yes, ‘collect.’ They have specially trained people to handle the neuro-psychological shock, and CSPs are easy enough to transport (a sealed 55 gallon drum will do). As to what the authorities do with them? Well, the average secret government agency is going to have any number of secret archives, treasure vaults, and/or mothballed facilities in inventory: just toss these things in a display room somewhere. As a backup security system goes, having a CSP on ‘patrol’ is incredibly free from overhead. Just put them somewhere where nobody’s supposed to be anyway and everything’s golden.