Active Accounts & Account Safety?

[Maki]

So I noticed that you guys can get into and sell actively running accounts, with the original owner unawares.

I can't help but be worried for the safety of my own main and sides- they're not exactly loaded, but, you know. LOL

I was wondering as to how I can protect myself from you guys (lol) if you can really get into any account even with a little time and effort.