booing the opposing fighter, booing the opposing anthem (although personally I would respect it), giving the opposing fighter a lot of "stick"
The main problem with that is that many "fans" quickly swich from verbal... Edit: Booing the natinal anthem is low and a disrespect of the others "national pride". I tend to more like the sportsman-part of a boxing match but nothing against a "little" rivality.
That is very true, there is definitely a line that should not be crossed. Who defines where this line is though?