it getting hacked is probably the top concern. if an attacker can access my information on that site, they can steal my identity and conveniently also know exactly how much that identity is worth stealing. Not that not using the system is any guarantee that I'll be safe either. my data's already been leaked by Equifax so I'm expecting someone will try something eventually. scammers have already tried calling my mom, telling her I'm in the hospital but fortunately she was able to call me and I was able to say that I wasn't.
which is to say, that worry shouldn't stop anyone from trying their site.