The Brat

This pet peeve is actually less about the brat than it is about the parent of said brat.  I mean the parent that pretends like their bratty child just doesn't exist.  You know this person.  They're in the aisle of Target, at the next table in a restaurant, in the movie theatre (there is definitely a separate pet peeve on that one), they are nearly everywhere you go.
Picture this: The child is doing something completely beyond the realm of public acceptance.  This includes a full range of possibilities, from small scale screaming to a full fledged grand mall temper tantrum.  And the parent, yes - the one person truly responsible for the child, is doing an Oscar worthy performance of pretending that the child is not even there. 
For instance, once I was at an Italian restaurant with some fellow diners (who shall remain unidentified) when a small child at our table, who had spent the evening under the wandering eye of a parent doing a stellar job of ignoring his presence, skewered a meatball in a moment of anger.  He raised the meatball - not to his mouth, mind you, but to fling it across the restaurant where it landed squarely on the back of a woman wearing a white blazer.  I am not making this up.  And what happened?  Nothing!  The wandering eye glorified in looking intently between a bread stick and the crown molding.
The child is not going to disappear, no matter how much you ignore them.. Probably better to man up and admit to their presence - however bratty.  It could be good for both of you (not to mention everyone else at Target).