Unhelpful spectators

A premiership linesman I heard recently was saying how difficult it was to go from the top level of football, with its huge crowds, to local matches, where the crowd consists of a few subs, a couple of mates, a couple of girlfriends and a man with his dog. At the top level the linesman knew he was being abused, but couldn't make out any individual comments and so didn't worry about it.
But at the park level, where FatRef plies his trade, angry comments travel unimpeded across the field. At a recent match the shouted comments of an assistant manager were so annoying that I halted the game and told the manager I would abandon the match unless he dealt with his assistant. That was a youth game, where, as all refs know, fathers get to live out their fantasies of being good footballers through their kids and think it's fine to scream insults at all and sundry.
Running the line this afternoon at my son's under-18s match (I wasn't appointed, so I was a club linesman and didn't give any advice on fouls to the referee, whom I knew), I met one of these charmers.
I'd hardly raised my flag in anger before a complete stranger behind me began telling me what a uselss linesman I was and that I shouldn't be allowed to hold the flag. In previous years I might have engaged the gentlemen in some banter, but I've learned to bite my tongue and keep quiet, even though I'm tempted to shove the flag where the sun don't shine. The gentlemen, no brain surgeon, ran out of weak insults after a few minutes and shut up, although I'm sure he would have chuntered on for the whole match if I'd encouraged him.