yeah, my LFS has them in their tanks too. I break his stones all the time, but he just seems to let em go.
Doesn't make them good just 'cause the LFS has them. I don't think you'll get an argument on this.
Exterminate them!!!!
Do a search on bubble algae. I have read several different methods of getting rid of them. I know foxface rabbitfish eat em and some emeralds do also, but manually removing them is probably your best bet!