Backstory: my group of friends is largely, but by no means entirely, privately-educated. I would say about a 70/30 split. I have one friend who seems to have a real chip on her shoulder about not having been to a private school. She often refers to herself as a "pleb" as if daring anyone to contradict her. She calls anyone who was privately educated a "posh twat". What really gets my goat is that apart from being state-educated she had a VERY cushy upbringing - private music lessons, stay-at-home mother, big house in the London commuter belt...her parents own a bloody sailing boat for God's sake! They obviously weren't hard-up! She acts like I'm a Rothschild when a) my mother went back to work when I was a toddler and b) my parents live in the North, so my childhood home probably cost a fraction of what hers did.
I really resent her acting like she's had such a hard life and I've had everything handed to me on a plate. Not to mention it seems pretty disrespectful to people who actually did grow up in poverty. There's one guy in our friendship group who can be a bit of an arse about people's "class", but I really can't imagine anyone else looking down on her for the school she went to.
...and the person I know also has a cruising boat and is happy to vilify loudly such nasty capitalist concepts as landlords and private schooling-despite being one and partaking of the other for her DCs.