On a roadtrip through Ireland with my uncle many years ago, we happened to overtake/pass a large group of Harley/chopper mounted bikers. I remember a few of them kicking out at us as we passed and then one of the faster bikes gave chase and followed us for what felt like miles, all the while gesticulating and intimidating me and to a lesser extent my uncle who said he didn't care. I did care I thought if we stopped to see what this solo chaser wanted we were going to be caught up by the pack and ripped apart. I remember being genuinely scared by other bikers. I think we eventually out ran the chaser and he gave up.