SOLDIERX.COM Nobody Can Stop Information Insemination

OK, if one wanted to hack a forum username to obtain further info about that person (in theory) then can it be done?

I'm not asking for anyone to do it, and I'm not asking for a walkthrough - however, was just hoping for a few pointers such as:

- can it be done?

- what kind of skill level would the individual need to pull off such a feat?

- I assume brute forcing would leave lots of evidence on the server so wouldn't be a viable option?

- What areas of knowledge might one need to be proficiently versed in before trying this?

Thank you in advance for any feedback.