here in France they've taken a more top-down approach to bike theft - apparently every bike now is "obligatoire" to register in a national database and every bike has what they're calling a VIN, like a car. the vendor I've seen in various shops here is Recobike:
apparently they use a "chemical welding" (glue?) process to permanently attach a tag to the frame. not sure how I'd feel about that on a high-dollar rig but it's not bad-looking.
as for the out-of-control bike theft from SF garages and the impunity with which theft rings operate - le sigh. but I think maybe "hardening the box" might be a better approach than more heavy chains (assuming you own your place, obvs). unlocking a bunch of kryptonites would make me less likely to ride (bummer), whereas installing high-security garage doors and electronic combo door locks don't add much/any hassle but would be effective against most intruders. also lots of cameras with defined areas of interest that cause alerts/alarms. maybe throw a Lemonade (etc.) policy on my bikes too, whether homeowner or renter. fast and easy.
what's next, vigilantes? seems likely.