I came across this info and found it to be practical. I understand our bag handles are different but the same idea could be implemented.
I am a huge fan of the Projekt D helmet lock, simple, effective design.
I know a bunch of guys that use the free gun cable locks to fasten their helmet to their motorcycles.
Cheap, and keeps helmets from walking away, at least to keep the honest people honest.
Indeed. I used a few gun cable locks for years to secure bags and even my jacket at times. But I have so many better options
http://www.advancedsporttouring.com/Concours_Helmet_Locks_p/c14-10.htm
http://advancedsporttouring.com/v/vspfiles/instructions/Helmet%20Lock%20Install%20Instructions.pdf
Bolts into the rack bolts, nice n clean
Key blanks for more keys can be purchased at any key cutting place near you.
It's more of a "I want to not have to deal with my helmet or worry about it hitting the ground for a while" thing for me. If I want security, I'll put on the bags.
I will hang the helmet on the hook, even if I am not locking it- that way there is no way it will accidentally fall off the bike (yes, I have done that before). For any non-local trip, I wouldn't have any room in the bags for the helmet anyway (a helmet will consume 100% of one side-bag).