From a video excerpt of a flashraid in Washington DC on April 3rd 09, Anonymous protester, Anonsparrow, encounters a Scientologist that has a small rock in his hand.
Mr Rock Handler is about to leave, but then returns to ask the protester if he knows anything about Scientology. He then shows him the rock, puts it on the ground, and retorts, suppress this.
So, for all you music lovers out there, I'm taking this as Scientology's way of saying that they want you to suppresses rock. I guess they don't want you to compare it to the chalkboard scratchings that L.Ron Hubbard assembled in a studio in the 1970's(?). I'm not even going to embed the video, it's that awful.
I'll just leave you with this, "Rock On, Anonymous!", and these videos.
Scientology: Suppresses Rock
Rock Me, Amadeus Remix
Twisted Sister - I Wanna Rock (Live 1984)