Each to his own and I understand the frustration of those who joined in. I wouldn't do it. I just think it's a bit slime fan-ish. They have been known to boo their team, throw coins and other projectiles.
It's an emotional ride for fans and we all react differently.
If anything, hopefully the team will be ashamed and vow for that not to happen again.
The world's against Manly. It's horrible to see Manly against Manly.