http://www.leginfo.ca.gov/pub/13-14/bill/sen/sb_0951-1000/sb...
One thing that CTIA did while lobbying against this was to announce their "Voluntary Commitment" as an alternative:
http://www.ctia.org/policy-initiatives/voluntary-guidelines/...
As you can see from the reporting and the text of the two documents, one of Senator Leno's biggest disagreements with the industry is about whether the mechanisms should be opt-in or opt-out.
An issue that I have raised indirectly on behalf of EFF is whether someone other than the phone owner has the technical ability to kill the phone, and, if so, whether the phone owner can reverse this on their own. Neither Sen. Leno's text nor CTIA's definitively answers this, and we haven't seen it publicly discussed very much.
The worst-case scenarios for me are if a government can order a carrier to disable the phones of everyone who attended a particular protest (or everyone who has recently exchanged SMS messages with a particular person), or if there's a master list of keys sitting around on some hard drive that could be used to disable every phone of a particular model in an entire country.