doll some random evil faggot could run anything on anybody's computer thats browsing the sharty which could be either more datamining, a redirect to a bad site, putting the victim in a botnet possibly spamming/ddossing the sharty or any other site, running other vulnerabilities that could possibly be in some people's browsers (escaping browser to get remote code execution and doing something like downloading malware and running it), steal a gempass/mod/admin/whatever credentials