Mark Cuban has a blog post entitled Ripping on Gootube... Again which introduced me to a Youtube trend I hadn't even noticed. He writes

Take a look at Decembers Top Viewed English Videos.
Most Viewed (This Month)
...

Britney Spears caught without underpants 01:07 Added: 3 weeks ago From: tylermcgregor Views: 1408363 3523 ratings

Me and My Cell Phone -- The past 25 years 00:59 Added: 1 week ago From: VerizonWireless Views: 1373397 5731 ratings

BRITNEY'S SKIRT FLIES UP, CROTCH SHOT SHOWN AGAIN, CHECK IT! 00:29 Added: 1 week ago From: wylinoutbitch Views: 1341496 3299 ratings

Matt Damon Does Matthew McConaughey 01:28 Added: 2 weeks ago From: CBS Views: 1277719 3895 ratings

Go through the list. Only the StarWars PSA, the Christmas Tree Jump and PowerTool Racing are really user generated content. 3 out of 20.

From there you have a contrived 12 days of christmas that is one of thousands of promos for Youtube users themselves trying to build a following. Is this social networking at its best ?

From there we have commercials or promos for movies, for tv shows, for blenders, knives, for music videos and for a phone company. Then we have the most popular of Youtube videos these days. The fake Porn thumbnail with headlines of. Britney, Paris, whoever, nude, in the shower, wherever, doing whatever. 5 of the top 20 are fake porn.

The fact that the professionally produced content is more popular on YouTube than amateur content isn't that surprising. By definition, professionals can put more time and effort into producing high quality content which is why their content is more popular. This is true in almost all areas of user generated content areas including blogging, see the Technorati Top 100 for proof.

What is surprising is how popular 'gotcha' content which pretends to be soft porn turns out to be a practical joke has become. The two fake porn videos linked above have been viewed over a million times. The interesting question is whether Google/Youtube will do anything to curtail this trend. This is likely a cause for user dissatisfaction on the site based on all the negative responses I saw in the comments to the videos, however there seem to be enough people who find it funny that this isn't a clear case of spam nor can it be voted down by the community since a lot of people may vote them up since they find them amusing. 

As Mark Cuban points out in his post, this is one of those perennial problems with social software. If trends or people that are harmful to the community show up there isn't a clear way to deal with them without it seeming like the heavy hand authority slapping down people trying to have fun and express themselves. On the other hand, I doubt Google spent $1.62 billion for Youtube just to watch it turn into a haven for fake porn and other forms of griefing.