The only reason NOT to sue, I suppose, would be to try to keep your anonymity but in the days of OSN hasn't that ship sailed?

I suppose the sensible thing to do, given your current desire not to press it, would be to keep playing elsewhere as usual and see if they're now "on to you" and then decide whether to sue.

If they seem to know who you are and flat bet you then there'd be no down side to suing, but if not and if you can continue to card count as before then maybe they're not on to you.

Tough call.