Sorry but look about as worthless as teats on a boar.
Of course it's useless. Game designers come up with the most ridiculous weapons, especially if they're in California and have never touched a real gun.
But then, look what some people on arfcom hang off their rifles...
On the other hand, Masamune Shirow, who is in Japan, came up with a sniper rifle with a satellite downlink to show crosswinds as shifting color patterns, which struck me as an incredibly useful idea.