The flaws is usually in the file name or how available the image is.
exactly. for one thing if you take a picture online, but upload it somewhere else, then safe it from there, the file is something completely different. i have faced this many times, too.
@Iju: next time just use Google search by image. Wherever that image originated is sure to pop up.
i got this pic years ago that i put in my photobucket, so i'm not too sure it would appear.
it was someone's signature from some forum site, and i think even they didn't know the anime.