We don't do it at all. The only civvy a/c pinged are the Cobham guys.
We did intercept a few Virgin a/c after 9/11. It was sanctioned by Mr Branson & proved to be a good learning tool. Interestingly, the a/c intercepted had no passengers onboard & were being flow specifically for the training scenario.
It was quite funny watching the F3 do it's best to turn with a 747 at high altitude... Couldn't help but suspect that the Virgin crew knew exactly what they were doing. Probably ex Tonka drivers!!