The California Location Privacy Bill (SB 1434) proposes to require cellular phone companies to stop their practice of giving your location data to the police without a warrant. Phone companies would still be allowed to give your information to the police if they got a warrant, first.
Naturally, the CTIA -- the mobile carriers' industry association -- opposes it. They say that it will be "unduly burdensome" to have to say no when the police show up without a warrant, and to keep track of how often they give your information to the cops, and why. Cyrus Farivar has more on Ars Technica:
In an April 12, 2012 letter addressed (PDF) to State Senator Mark Leno (author of the bill), CTIA says it is opposed to SB 1434 because it may "create confusion for wireless providers and hamper their response to legitimate law enforcement investigations." The group also states that "[the bill will] create unduly burdensome and costly mandates on providers and their employees and are unnecessary as they will not serve wireless consumers."
Earlier this month, the ACLU said it received over 5,500 pages from 200 local law enforcement agencies about their tracking policies. The organization concluded that "while cell phone tracking is routine, few agencies consistently obtain warrants. Importantly, however, some agencies do obtain warrants, showing that law enforcement agencies can protect Americans' privacy while also meeting law enforcement needs." In short, it seems like law enforcement can stay within the law, even when it takes the trouble to get a warrant—how is that confusing?