>>372855658
Nah they're called plasterboard props and generic camera clamps will work just fine. 
I use them too, they've been solid for 3 years now. Good for rented apartments since good stablity without drilling.
I can't say that you can't knock them over since if you do fall into them or pull on them they will come loose, but I've not had any issues at all that didn't involve me.