Idiotic effect

Some idiot is spawning what i think is some effect, but i have no way of figuring out who it is.
A cleanup doesn’t remove it, only way i have found to remove it so far is a map change.
Looking something like this:

In an xray:

Any speculations on what it is, and how to remove/uncover the bastard?

Wall Hack Much?

I’ve seen this done with major DoF nodes before. It’s really terrible and I’d like to know a way to stop people from doing things like this too…

Oh wow.
That sure is bad.

hack 4 sure. well, you have to disable custom content on the server I think.