The reason i said NO dont is due to these points.
You yourself commented a member stole it and placed it in thier profile ( and the site uses profiles for banners)...so they didnt lift it from your site.
more important ,when a damages claim is put together l assume they look at the $ loss of one party and the gain of the other and in this case it seems minimal ?
If your still unsure I guess the best advice is " Consult a lawyer "
