Well, a lot of this may well have been fiction, but my views are coloured by having lived in Australia for a few years, the bikies (as they're called in Straya) have a shocking reputation there, there's the "Milperra massacre" from back in the 80's, when half a dozen were killed in a shoot-out, a bloke was beaten to death at Sydney airport a year or two back in a bikie fight (can you imagine the uproar if it had been Heathrow?) and there were a few killed at a car show or similar I recall too. These are just the main stories that make the headlines, there are heaps more. And bear in mind that Dunnunda there are only a few hundred bikies in total. Google it, makes incredible reading.
Don't know as much about it, but there's some bad stories come out of Scandanavia too - attacking rival clubhouses with rocket launchers anyone? Even the militant wing of the Caravan club don't go that far.
So while Ogri and the like are I'm sure full of decent guys, the clubs that most associate with MCs have a few naughty people as members.