The term sub-lethal refers to weapons which can not cause lethal injury without substantial modification, now no-one at the home office has noticed this, but the new "glass-shatterer" rounds (check out the I didn't know JT made riot gear-thread) currently available are capable of causing fatal injury, this means a marker is capable of causing lethal injury by simply re-loading, so all it takes is one lunatic and we have problems. As I said earlier, I've been asked by a night-club doorman if you can load them with anything else and where he could buy one (I could hear his cogs ticking so I said no), he works in Newcastle, 200 yds from a shop selling brass eagle entry-level markers and within twenty minutes of a "pro-shop". So there's one person I know with access to kit and the capacity to do something ill-advised.