[sofixa]

Yep. I'm trilingual English/French/Bulgarian, and i have all three as languages in Google search, and they're mixed up too often. I can understand Google proposing the French spelling of an English word and results for it, but almost every time when i search something in Bulgarian i get results in Russian, even when i use words that don't exist in Russian. The languages aren't even that close, and they aren't the only Cyrillic ones...

[Joker_vD]

Well, those are quite close to each other from the orthographic point of view, I guess: Ukrainian or Serbian are visually very distinct from either Russian or Bulgarian, while to tell the latter two apart you need some actual knowledge about the differences of those languages: say, that the abundance of letter "ъ", words ending in "ът"/"та"/"то" and tons of prepositions (i.e., often repeated two-three letter words) are a pretty good indication of a Bulgarian text.

[kakkun]

Yeah, it's annoying, especially since I've told Google explicitly the languages I know. I do suppose that a lot of people haven't set their languages, and the automatic detection works well enough, most of the time.