Originally Posted by Joannah Cramer

Ahh but there's the thing, how do you tell that IP is of someone who happened to post at that time, and not one of X readers of either this or totally different threads, who were just browsing at the same time?

Not to mention, someone posting in thread would generally have to view it first... so the timestamp of the moment they loaded your signature image wouldn't actually match the timestamp of moment they posted their reply... add to it that time difference would also vary depending on how long it took them to make the reply... oy.