Lumiya, the 3D Second Life viewer for Android devices (which I'm proud to have as a sponsoring partner of NWN) is getting a powerful new feature in an upcoming update: a block/mute list. (Sneak preview above, though it'll be polished when it's pushed as an update.) Lumiya developer Alina Lyvette is adding it, she tells me, "because of the recent spike of griefing behavior in SL. I should have done it a while ago, but now, as it seems, there's an increased need for it." Go here to get it in the next update.