Apparently there is a bunch of really 'thrifting' individuals which bougt cheap Diablo 3 keys from some shady sites, and these keys turned up do be for a Russian region, allowing only Russian client language to be used. Now they are complaining, and, the funniest part, blaming Blizzard.
I would never thought that Europe has so many proverbial misers who would risk the entire purchase for negligent spare...