Any breed can have nasty males.
I have hard people say that leghorn males are nasty. However, I have not experienced any more mean leghorn males than many other breeds. I used to breed lots of leghorns back in UK but only came across one nasty male. They are particularly flighty & not singularly disposed to be being friendly. I found them intelligent, fast & great fun. Also given to screaming as if they were being tortured when handled.