Too many people still believe the old-fashioned, outdated, dangerous, (and cruel) way to treat aggressive behavior in dogs is with confrontational techniques. People who call me for help have almost always tried to "dominate" their dog when it growled. Qualified trainers and veterinarians have known for some time that these confrontational techniques won't treat the problem, and almost always lead to even more aggression.
Unfortunately, there are charismatic and entertaining people on so-called reality shows that continue to perpetuate the dominance and confrontational techniques, much to the detriment of dogs everywhere.
Finally, scientific research is being done proving that these confrontational techniques lead to more aggressive behavior. See the 2009 published research from the University of Pennyslvania.