An iGoogle account lets users pick personalized features such as their own interests and hometown, but they don’t have to. On the free wireless service, which could detect users’ locations according to what access point they are using, people who log in under a personalized iGoogle account may be able to get content specific to where they are at the moment, Sacca said.

None of these users would have their Web visits tracked, he said. What would be tracked, with or without an active iGoogle account, is the unique address of the device. Google will watch the size and frequency of each device’s data transfers, as well as its location. This is to prevent abuse of the network, Sacca said. Whatever information is collected will be discarded after no more than 180 days, he said.

As for targeted advertising covering the costs of the free service, it won’t happen, at least in the beginning.

"That could be done, but it’s not the prime motivation for the project," Sacca said. "We have not put an emphasis on building a layer of location-based services yet."

Instead, Google sees the service as an experiment, like the Wi-Fi network set to launch soon in its hometown of Mountain View, which he said has no revenue model.

"I’m in the very exciting position of being able to start and build stuff without having a short or medium-term [return-on-investment] model," Sacca said.

Google seems to have backpedaled on its plans since the privacy advocates wrote letters and eventually met with the company, said Nicole Ozer, technology and civil liberties policy director at the ACLU of Northern California. "I think it was a surprise to both Google and the city," Ozer said.

The city used the letters from the ACLU and its partners in crafting its RFP, asking potential providers how they would address those concerns, according to Chris Vein, executive director of the city’s Department of Telecommunications and Information Services.

Google’s RFP response didn’t lay a clear blueprint for an intrusive service, but the city deserved to know more about the plan, Ozer said. She still isn’t sure users would be sufficiently protected. Although there are ways to avoid data collection, most consumers won’t figure them out on their own, she said.

Danny O’Brien, activism coordinator at the EFF, doesn’t think the critics can take credit for a change in Google’s approach, but he also doesn’t see much reason to celebrate. The company’s plans could change, so any safeguards would have to be built in to the contract, he said. And no matter what the company does with user information, it could become a "honeypot" attracting government investigators, raising the specter of intrusions like the illegal wiretapping EFF alleges AT&T conducted for the National Security Agency, O’Brien said.