"Is revenge wrong?"
It bloody well is if you take revenge on INNOCENT PEOPLE. I have no problem if you take revenge on the people who wronged you but when you don't care how many innocent you kill in the process you're no longer going for revenge, you're just a murderer and have lost the right to live, I don't care what your reason is how ever heartbreaking it might be, it doesn't give you the right to hurt other innocent people for your "revenge".