To add - if a person's or company's or business' domain is very much associated with the real identities, then it is worth paying or even going to court to settle the matter.  

If the domain doesn't really matter, and folk know how to find your place on-line no matter what the domain name, then let the sneaky guys swipe it.  But there is a downside - the sneaky guys could also misrepresent themselves as you or your business, and then you will be in the hot seat explaining it isn't your domain anymore.  

So, one has to use some judgment in these matters for a personal or small business, but for large companies, they'll probably have their own IT and legal people on the case.

Eternal Hobbyist