Barricades depend mostly on the people inside of them, not the barricades themselves. Some spots are cheap, but if you have a good player in there, it's impossible regardless.

So unless you want to start banning people for paying attention to barricades, I would still like to state: The only barricades that should not be allowed, are using the shelf on snoopie, the Red Room, or the first story of the blue building on 4corners.

The last one you can let slip if you want, but I was the one who pretty much first discovered that to my knowledge. After that, people copied, I saw it was just too cheap. So usually I ask people not to barricade there.