There seem to be a ton of threads lately where people post screenshots of their co-ops they just made where someone joined with significant number of eggs and then they accuse them of cheating.

Here's what's actually happening:

Many people, including myself, run a contract solo for awhile, sometimes til just before the timer runs out. THEN we join a co-op. This essentially restarts the clock for us, since the timer for everyone on the co-op resets to whatever the co-op creator's timer is. BUT, we also bring whatever eggs we've collected so far while we were soloing.

Cheating does happen in co-ops, and I've seen it a couple times, but what you typically see when that happens is that you've been running a full co-op for awhile, and then someone's egg count takes a sudden, ridiculous jump. This is entirely different from what everyone keeps posting lately.