When I was publicity officer for one of the university societies in Aberystwyth, everything had to be bilingual and we had to get all emails and publicity materials translated into welsh. I was warned not to use any machine translators on the Internet. This is a good reason why you shouldn't:

Cyclists have been baffled by a new road sign which warns: "Your bladder disease has returned."
The sign - in Welsh - was meant to tell them to dismount at roadworks. But council chiefs made an error using an online translator and confused the words 'cyclists' and 'cystitis'. Amended signs are now being put up as soon as possible in Penarth, near Cardiff.
Welsh speaking cyclist Matt Lloyd, 27, said: "I thought someone was having a laugh. I've never even had a bladder disease."

I read this in the Metro newspaper on the train this morning but the story was also covered on the BBC News website, where they have a picture of the sign as well.