The only time I lock my helmet on the bike is with a cable lock through the visor aperture, full face helmet of course. It seems to me that all anyone has to do when it's secured by the strap is just cut the strap and sew on another one?
Just bought this an hour or so ago,and a years extended warranty,,wee run back from Edinburgh, no dramas, no rain and now a space in the garage sorted beside my restored 400four,,Tiger feels great,