I personally have never had any problems at Rugby, home or away. Even though I follow one of "those clubs with a reputation" that some posters are inferring to.
Unfortunately however, I have witnessed various incidents involving various idiots supporting Fc. Biggest of all, of course, being Good Friday 1981 at the Boulevard. The main centre of the ruckus took place at the Gordon St end, opposite to where I tended to stand. To this day, no one is totally sure who started the brick throwing (renegade Tigers fans has always been a popular view around these parts).
Things appear to be a little quieter these days, although we still do have the odd spot of bother in the NE corner of the KC. This is usually down to p!ssed up 12 year old chavs from Orchard Park getting uppity when things aren't going too well on the pitch.
Co-incidently, chav corner is again the opposite end to where I stand/sit. I obviously must be fraternising with a better class of people when I attend my favourite sport, thankfully.