Plastic surgery:
I don't have a problem with non-obtrusive fixes ie eyelids, nose, or whatever you want -- in principle. Bom, one of the funniest pop stars otherwise, has ruined her face. Totally botched, beyond repair. That's a shame.
I'll give the benefit of the doubt to anyone who specifically says they haven't done anything, unless it's blatantly clear that they have. Taeyeon has specifically denied it, Tiffany as well (Hyori went to great lengths to prove it). I don't see any reason to doubt that unless reports to the contrary show up. Some SNSD members may have had something done - who knows, it's likely. T-ara's Soyeon has admitted minor work, same with Hara, but at least it doesn't look bad so it's whatever.