Well you ain't far from me and I haven't see one yet. But I know what you are talking about. They are big out in Texas where my stepson is stationed (Ft. Hood). Mostly 1% biker gangs (drug related) have them or at least originally that was the case.
Now many regular (non gang) bikers are starting to ride with them. They are basically a weapon and can also be used to bash out the window of a cager that may cut one off etc.
You just slip the lock hasp off the clutch lever and it becomes like a weighted sling type affair. I've heard they will break a lever after after enough time though.
I would not advise using one (for any reason) especially in Florida since many of these cagers down here have guns and from the evening news I see that they will use them in road rage incidents quite often it seems.