While this behavior is ridiculous, dangerous and reprehensible wherever it may occur, it doesn't occur only in Morgantown, WV at WVU. Its mentioned about WVU and used to reinforce stereotypes like most of the posts in this thread, but it does occur in many other places.
It actually happens at Michigan State as often as it does at WVU.
Michigan State fans rioted after beating Ohio State for the B1G title last year in December 2013 -- setting 57 fires, rioting and flipping cars.
http://bleacherreport.com/articles/...ns-riot-after-spartans-win-big-ten-title-game
Michigan State fans rioted, burned couches and caused extensive property damage in Feb. 2013 after MSU lost to Indiana in basketball. The article I've linked mentions also a 2008 riot involving 3,000 to 4,000 people causing $150,000 in property damage and a 1999 riot after MSU lost to Duke in the Final Four.
http://www.wilx.com/home/headlines/Couches-Dumpster-Burn-After-MSU-Loss-to-Indiana-192146661.html
University of Minnesota fans rioted after losing in the Frozen Four in 2013 setting fires, damaging cars and requiring hundreds of police in riot gear to use tear gas to disburse them. The article references 2003 riots that were much worse after Minnesota won the Frozen Four with torched cars and looted stores.
http://theweek.com/speedreads/index...ot-after-hockey-title-loss-mess-with-reporter
Happened in Manhattan, Kansas after K State v. Kansas football games in 1984 with 8,000 fans overturning cars, uprooting street signs, smashing windows and looting and again in 1986 with 6,000 rioters and cars being torched and rolled over and it was said that nearly every single building in Aggieville had its windows smashed out.
http://en.wikipedia.org/wiki/Aggieville_Riots
There was rioting on Marshall Street at SU in 2003 after we won the championship with fires being set and objects thrown at riot police who were there to keep control.
http://www.youtube.com/watch?v=MMbe5rSbu3Y
Happens in the pros too:
L.A. Lakers fans rioted after winning the NBA finals in 2010 setting 19 fires, jumping on and damaging vehicles, torching cars, beating people, and hurling bottles and rocks at responding police officers.
http://www.csmonitor.com/From-the-n...-get-ugly-after-LA-beats-Boston-in-NBA-finals
Lakers fans did it the year before too, setting fires, damaging vehicles, looting stores, attacking a taxi and other vehicles and even setting fire to one police car and damaging another.
http://www.inquisitr.com/26122/la-lakers-fans-riot-outside-the-staples-center/
Happens outside the US frequently too:
Vancouver Canucks fans rioted in 2011 after losing the Stanley Cup finals with fans burning 17 cars, 2 police cars and a fire truck, looting stores, Police finally got control with use of tear gas, pepper spray, police dogs and batons.
http://www.cbc.ca/news/canada/british-columbia/riots-erupt-in-vancouver-after-canucks-loss-1.993707
Happened in Montreal after the 1986, 1993, 2008 and 2010 NHL finals.
http://sports.espn.go.com/nhl/playoffs/2010/news/story?id=5185068
In fact, there's a whole Wikipedia site about sports riots.
http://en.wikipedia.org/wiki/Sports_riot