Ditto to a lot of the above, but I remember Blackburn away 73 being a bit silly, as was Halifax 75 and Sheff Utd away 81 (we got chased and hid in a curry house for a couple of hours so not too bad really). In terms of non-league you could always rely on a few nutters from Wigan, Scarborough, occasionally Boston, Mossley, Runcorn, Macc not forgetting Vics in the APL when they were the Boxing Day / New Year derbys. As Gazelle says in the 70s there was a chance of trouble anywhere - does Brian Flynn remember leaping into front gardens at Gainsboro for example - first game of the season too!
Without doubt though the scariest was Frickley away in the cup mid Miners Strike - I'll never forget a couple of mounted police chasing a bunch of blokes across the slag heap in the 2nd half . If I remember rightly it really kicked off when some Met coppers turned up after the game had finished, maybe we were instrumental in the dismantling of the Trade Union movements traditional shock troops by virtue of a jammy Phil Gardner mis-hit - no probably not.