For defenders and defensive mids to foul hard, even take a yellow, if the opponent is cheating and diving. Back when i played, it was just a known fact. Marcelo went way overboard obviously and should not have gone after him like that... that was crazy.

Mou is making sure we are getting our own justice if the refs and governing bodies are unwilling to. He's taking very tough measures.

I guarantee you players are going to stop diving if they sense that there is a real intent on the physical play. Self preservation is a stronger force than winning an oscar.

Just mentioning why Mou is doing this. Barca diving is actually decreasing a bit as a result... they are actually afraid.

It is standard as you said, they're acting as if its the first time its happened. Barcelona's weakness is physical play, that's why they will always make a big deal out of it.

This video shows it all, if you even want start it at the 4th minute. Just see the nasty nasty fouls that happens.

Real Madrid players, have done some really bad tackles in the last games, everyone can see that.
I don't get why Barcelona players make a big deal out of it though, there is a difference between a murderous tackle and a hard-bad one. (not to mention, they dive always, even in light touches, that is provokatory behaviour there but anyway.)
I will not excuse Marcelo's grotesque tackle to Fabregas, that was a really bad call from him, even if it was mostly an unleashing of emotions reaction responding to the theater-award a few Barcelona players deserve.