Re: How covert was it?
I had a bright red warning light in my car that warned me that the airbag in my steering wheel was faulty. Since I wasn't too enthused at spending AUD$1,500 to get it fixed, I just covered the annoyingly bright bugger with a couple of pieces of black electrical tape. It's not rocket, or in this case, camera science.
If they remove their identification when on duty at protest marches that could result in a bit of push and shove, then what's to stop them having pre-prepared; tape LED for the covering thereof.