Lots. It's not just the Arabs (as you hardly see them), but the higher caste Indians who do it the most.Got some juicy examples to share for our anecdotal knowledge?
One example that stands out; I was in a busy restaurant with colleagues, and all of sudden we hear loud shouting. It's not a fight between patrons, but one of the managers yelling at the servers. Imagine a drunk parent yelling at the top of his voice at a 5 year old who's just standing there looking terrified.
It was so loud we couldn't ignore it, so we called over the manager and told him what he did was unprofessional and if he didn't stop we would complain to someone higher up. The manager (another Indian) apologised and stopped.
After that, service became pretty bad. Later on someone was taking photograph of one of the meals and one of the Indians who we earlier had saved came up to us and rudely told us photography was prohibited.
It didn't make sense at the time but in hindsight it does. Those Indians probably saw that momentary act of compassion as a sign of weakness.