Hmm. I was getting this, too, for one page of my game library and came here to see what was up. It seems suspicious, since I wasn't spamming anything, or even getting much in the way of site page loads or purchases or any kind of unusual traffic. But in the time it took me to type this, it seems to have disappeared, so I guess the itch devs are on it. Might be someone who figured out how to do an injection attack with comments or something, and the devs have managed to filter it.