Perhaps the biggest threat to Google’s increasing dominance of Internet search and advertising is the rising fear, justified or not, that Google’s broadening reach is giving it unchecked power.

This scrutiny goes deeper than the skeptical eye that lawmakers and the Justice Department have given Google’s proposed ad partnership with Yahoo. Many objections to that deal are financial, and surround whether Google and Yahoo could unfairly drive up online ad prices.

A bigger long-term concern for Google could be criticisms over something less tangible — privacy. Increasingly, as Google burrows deeper into everyday computing, its product announcements are prompting questions about its ability to gather more potentially sensitive personal information from users.

Why does Google log the details of search queries for so long? What does it do with the information? Does it combine data from the search engine with information it collects through other avenues — such as its recently released Web browser, Chrome?

Data gathered through most of the company’s services “disappears into a black hole once it hits the Googleplex and it’s impossible to track that information.”

Google — whose corporate motto is “Don’t be evil” — generally sees such concerns as misinformed. For instance, the company says it stores the queries made through its popular search engine primarily so it can improve the service.

But whether the criticisms are valid or not, they are probably indicative of the battles Google will face as it, like Microsoft in the 1990s, moves from world-wowing start-up to the heart of the technology establishment.

The September release of Chrome illuminated the budding conflicts.

To Google, the new browser is a platform on which future Web-based software applications might run most efficiently. It also is a sign that Google understands its growing power, since launching a browser is a direct challenge to Microsoft.

In other circles, Chrome provoked suspicion. One group, Santa Monica-based Consumer Watchdog, argues that the browser crosses a new line.

In a mid-October letter to Google directors, Consumer Watchdog said it had “serious privacy concerns” about the browser and the transfer of users’ data through Google’s services without giving people what it sees as “appropriate transparency and control.”

One of Consumer Watchdog’s complaints surrounds Chrome’s navigation bar, which can be used to enter a Web site address or a search query.

The “Google Suggest” feature built into the browser relays searches back to Google as you type, in hopes of anticipating your desires. Brian Rakowski, product manager for Chrome, said queries sent to Google through autosuggest feature do include data like a user’s IP address. But Google logs just 2 percent of the data brought in through “Google Suggest,” to improve the feature, Rakowski said, and anonymizes the data within 24 hours.

“You’re flying blind without that information, so we have to collect a little bit,” he said. “But we’re really (collecting) the bare minimum we can to provide that service.”