I'm assuming you mean "XSS or CSRF". In both cases the first 2 letters denote "Cross Site".
But, I'm picking hairs, and as you say, the guy just lost a shed-load of coin, so mostly sympathy (with a bit of urge to educate) from this end.
EDIT: Sorry, your comment was slightly ambiguous, I apologize for picking on a typo, I originally thought you were saying that XSS and CSRF had nothing to do with "Cross Site" which, upon reading again, I noticed was not the case. (Also, I made the same typo (CRSF) while typing this and only caught it just before hitting the submit button!)