I've hit guild LFM's before, whether it be Cannith Crystal or not...Usually I'll get accepted. :P I also know what raid they're running and am very experienced in running it so that's likely why I'm accepted. Either that or they need someone to point and laugh at. Either way I get phat lewtz! Point I'm trying to make is, if you aren't in the guild and you hit a guild LFM, it doesn't necessarily mean you'll get declined. Of course, if they don't know who the heck you are and you try, you'll probably get the decline right fast. lol :P