No need to worry - not sure if any of you remember, but awhile back the same thing was happening. It didn't mean anything sketchy, it was just a weird glitch that kept logging people out and giving them a 3-character captcha. Nothing to worry about though - DPR was able to fix it then so I'm sure he'll be able to fix it this time as well. Still not completely out of the woods yet with the attacks, so this issue may persist for a bit, but if it is still happening in a day or two, I'm supposed to let DPR know.