A good bit of detective work. This is how you "do" journalism. Compare and contrast with the article about the developers of Flash that basically looked on LinkedIn and Google and called it a wrap.
He could have simply sold FJ to a better entity, somebody who can keep their shit together and use real lawyers. For better or worse, this whole thing brought a lot of attention to an otherwise-unremarkable content aggregator, and I bet plenty of people would be willing to take a shot at capitalising on such a frenzy.
This case is special. He took it personally and started acting on his own behalf, but in the initial demand for money he was just a proxy, as lawyers usually are.
How much money would a site like FunnyJunk take annually? I mean is this thing a hobby or is it paying the kind of money you could live on in New York (which I assume to be expensive)?
New York isn't quite as expensive as people make it out to be. It's not cheap - but you can sacrifice things like square footage, or short commute times to save on rent, which is most of the expense.
The article seemed to mention him complaining about money, but that could just be an indirect way of asking for donations, or re-inforcing the need for funding drives. (I've done this before, when we were hosting a VBulletin forum when we didn't really have jobs or much spare income in college.)
Depending on who hosts your content, these sites are fairly cheap to make and maintain. I have a few friends who make these sorts of websites and use imgur and other free services to host content. They cost on the order of tens of dollars a month. As for profits just look at their visitor stats and compare it to adwords.
Compete's analytics aren't great, but give you a ballpark (big, small). It's a pretty big site. Monetization against funny pictures probably isn't great, but given the traffic, it's probably doing very well.
Maybe because a couple of DMCA complaints stacking up in the states would result in the site being taken down with most economy-style hosting, and given the nature of the site they're bound to get a few...
Maybe the Netherlands just offer saner intellectual property laws.