I let my girlfriend use my iPad, she was playing a game and being quite violent with the screen, I told her to stop as she is very clumsy, and then later that night I saw my screen had quite a few scratches on it, including one that looks like the curvy shape of a nail, exact same size and shape of a nail... but people keep saying online nails can't scratch glass... are they wrong? it definitely looks like a nail to me and I can't think of it being anything else.