Its not true, from my experience on the Internet.
Nintendo fans and PlayStation fans tend to be about equal depending on whats happening at the time. If Nintendo consoles arent doing too well, then PS fans tend to have the upper hand. If PS consoles are in a hole, then Ninty fans tend to be the more prominent.
On another note, PS fans in general tend to be the louder of the fanbases. This is due to being "attacked" from 2 sides. Both Xbox fans and Nintendo fans get on at PS fans, but Nintendo fans and Xbox fans tend to ignore eachother. Think of it more as a "the enemy of my enemy is my friend" thing. PS fans will be fighting on 2 fronts, while Xbox and Nintendo fans tend to just get on at PS fans.
Thus, you get the illusion that "The Internet is flooded by Sony fans".
