Is it normal to viciously beat a pickpocket?

I was in Italy not long ago and a group of 3-4 men tried to steal my wallet. I was wearing hiking pants which were relatively tight around my legs with my wallet in a zipper pocket on the right leg. While on a somewhat crowded bus in a major city, I was standing close to a man in front of me who was facing me and there were also men on my side and behind me as I held onto a pole with my left hand.

At one point, I noticed that someone was leaning against my right leg, so I felt down and realized that my zipper pocket had been unzipped, although my wallet was still there. I was so enraged and that I punched the man in front of me as hard as I could in the lower ribcage just above his stomach, as he was standing entirely too close to me and I assumed he had been trying to steal my wallet. After I did this, he fell back a couple feet and the men around me also stepped away. I though it was on and I was going to have to kick some serious ass to defend myself. However, the man I hit was a giant pussy and didn't do anything even though he was bigger than me. I didn't realize at the time that the other men around me were in on this. After the punch I looked to my right side and saw a shrimpy guy with a terrified look on his face - he must have been in on this.

Nobody else, including the bus driver, did anything. I felt a rush of adrenaline and probably could have seriously injured the man I had already punched if I wanted to, and maybe I should have done just that to teach him a valuable lesson about messing with people. That man was probably in his 50s and was out of shape. I guess his role was to use his fat ass to box in a mark.

The pickpockets were clearly not prepared for a mark to use force to protect himself and did not want a physical confrontation. They got off the bus at the next stop. After they got off a friendly man came up and said that there were 4 men trying to pick my pocket and I did the right thing by punching one of them.

Afterwards, I was wondering whether I should have gone on the offensive and really kicked some ass. I think I knocked the wind out of the man punched because I did it quickly - I didn't have space to cock my arm back, but I quickly raised it and punched as hard as I could. After he moved back, he was stunned and I could have stepped into a straight punch at full force and then knocked him to the ground with an uppercut.

Is it normal to violently beat the shit out of a pickpocket? I wish I had used more force and knocked out that man! I don't think anyone would have come to his assistance as pickpockets are apparently a common nuisance on Italian buses and this man definitely had it coming