Hexing existing models/getting custom models from other games

There are other games that have a profusion of exellent models and textures that other users made for them, i was wondering what is the current policy on facepunch.

Do all the peoples porting css models to gmod ask for permissions?

I want to be sure of what procedures i DO have to do to avoid getting bashed because i released this or that hexed model.

As most model makers appear to simply LOVE to use super restrictive licenses that only give you the right to “look” at their work, and since they tend to split the work across several peoples, that means in most cases asking permissions to 5-10 peoples for just one model, which pretty much reduce the chances of getting a “yes” to … nothing.