Both... Well-known, established and trademarked names belonging to well-funded and large companies would be the most likely source of any hot water. They usually win such differences by being able to out-spend and/or buffalo their targets. If 'push came to shove', however, and the target had enough money, free speech would probably prevail in an 'intentially mispelled nomenclature for a domain name' type situation. Is whitehouse.org (or is it .com?) still a '****' site? You'd think if anyone could go after an intentionally misdirected and spoofed domain owner, the guvment would. (The official site is )
Then, you have some really smart people that have made killings on eBay purchases by searching on mispellings of eBay offered items - such as 'lab tops', 'dimond', etc. I once read a newspaper article describing how one man bought a $1000 dollar value laptop computer for only $40 that way. The man said he always finds unbelieveble bargains that way.
It really boils down, IMHO, to one's ethics and how far one will go to earn money. I know it could be done and how to do it, but my self-respect would suffer if I believed I had to resort to trickery and deceit to make money. If I know myself to be "up front" and "straight forward" in my dealings with people, then my self-respect feels good and grows as a result. Whether I make money or lose some is secondary, but it usually results in an overall net gain.
That is not intended to be negative towards anyone that does resort to such tactics. Many would consider it simply smart business strategy. I merely described why I, personally, would try other methods. I wish anyone using such tactics the best of luck. Just don't count on me to be one of your customers - I'd simply re-check my spelling and try again to get to where I wanted to be.
Cheers,
Tom