People being hacked since the last Server Check.

I don't believe you can anymore.

There was a rumour around that e-mail ID's were safer. Did anyone who got hacked randomly have an email user ID?

I'm not a computer-technical person, but by reading Eos' explanation, would the rationale behind having an email user ID be safer relate to the account packets in question being extrapolated (if say, the theory was true)?

Id's aren't random. All you'd need to do is understand how the packet in question related to the account it brought back and extrapolate it to use on other characters by simple incrementation and guesswork. Tedious, but going account by account will eventually strike it rich.