Last night (after midnight UK time), I was finding odd photos in searches, by authors who don't usually spam, but when I looked in the keywords, they 'wrong' keywords weren't there. That was even single words (e.g. my usual 'duck'). But being banned from forums and now sitemail, no way I could report it. Tough. It seems worse if you sort by downloads - try e.g. horse, cow, book.
The interesting thing is that there only seem to be one or two false hits in each search, making me wonder if it's deliberate (someone once told me there's a name for this, a known marketing ploy of 'teasing' with other goods)
Keyword phrases have been 'half broken' for weeks. For example if you put a keyword phrase in top box (before this recent glitch) it worked, but if you put the same keyword phrase, even in quotes, the words separate. Even if you click on a keyword phrase in a file, to see others with that phrase, it separates out into separate words, encouraging spamming.