Have to honestly say that I have just never seen it in my own experience. Yes a few knuckledraggers at games or pissed wankers in pubs, but that's it.
Of course we have a society which fails to make the most of the skills and talents of its various ethnic minorities. Nobody disputes that. What I do dispute is that there is deliberate, systematic racial discrimination on a widespread basis.
But surely those top two sentences contradict each other. They may be knuckledraggers at games but it's still you experiencing it, and it's those type of people that are largely responsible. Never got the 'pissed up' excuse either - you don't suddenly change your opinions due to alcohol, just lose your inhibitions to state what you already think at some level but control when sober.
Again, how widespread it is often depends on where you live and hang around with. I don't tend to see it but I live in middle-class suburbia and I have to admit it is far more white than the average population (although from what I can tell those of minority background aren't treated differently, but they may say different because there are people who do it that I don't see).
If I lived somewhere more inner city or somewhere like Foleshill then it may well be more widespread and visible.
The trouble is that you get a few idiots that racially abuse minorities, and understandably those minorities may well as a defence mechanism act in a way perceived more threatening towards white people. This can then gives the impression that minorites are racist towards whites and the problem escalates from a very small base. I've no doubt that the same situation reversed occurs in white-minority countries as well.
There is definitely an issue were there are people that use the race/gender/sexuality 'card' as thier go-to argument. Just as you see the knuckle draggers arguing about immigration as an excuse for their own shortcomings, so do others use issues like race, sexism or homophobia to hide theirs. There's been a couple of women on the last series of HIGNFY who were just trying to shoehorn sexism into absolutely every question and even my sister was sitting they saying 'would you please just shut the fuck up'. It undermines the argument because it's being over-used and causes average people to just switch off when the argument is totally valid because it's 'boy (or girl) who cried wolf". Worse than that, it provides ammunition to those who are racist/homophobic/sexist that the issue is being blown out of all proportion or being fabricated. Like when you have women who falsely accuse someone of rape - it does so much damage to protecting women from sexual violence because it puts that shred of doubt into people's minds.