My son is a "punk rocker"?

so my son has bin hanging out with these new kids that are very polite and all but have a weird sence of fashion such as spikey hair mohawks and hand made clothing and boots recently my son dyed his hair blue and cut it into a mohawk and has bin wearing boots and a hand made leather jacket with paint and studs i dont know why he is doing this oh and hes bin getting into some trouble............ is it my fault, did i do something, should i be worried, why is he acting like this , were did he get it from and why?