I am a bit of a fan of full disclosure. You report it via the in game report system their crap GMs read it and disregard it, at best it gets tossed on a bug report that never gets into the hands of someone that recognizes how broken it is. Clearly the right people look at these forums and if knowledge of the bug spreads fast enough (via their forums), they are forced to fix it. They can complain it has more people exploit, but if you keep it secret then just a small handful of players abuse it to get a massive advantage over everyone else.
It was the same way with the bugs regarded sabs and champs ignoring way more armor than they should. The info was around forever, but until people started making loud public threads on their forum, they didn't care.