Federal lawmakers are asking if Google Inc. violated the terms of its broad privacy settlement with the Federal Trade Commission, following a study in which it has been reported that Google is accused of bypassing the privacy settings on Apple's Safari browser to track usage on iPhones and Macs without permission.

Going by a report released by a Stanford University graduate student, Google has used a special computer code that tricks Apple's Safari Web-browsing software into letting them monitor many users.

Jonathan Mayer, a graduate student and privacy researcher, wrote about Google's Safari tracking techniques in this blog post. Mayer's findings got wide attention after the Wall Street Journal featured it in a news story.

This research result regrettably affirms that view as reality -- for, quite possibly, millions of users, Mayer wrote.

Reps. Edward J. Markey and Joe Barton, co-chairmen of the Bi-partisan Congressional Privacy Caucus, and Cliff Sterns, chairman of the Subcommittee on Oversight & Investigations, are asking if any violation of Google's agreement with the FTC has happened.

Google’s practices could have a wide sweeping impact because Safari is a major web browser used by millions of Americans, the lawmakers wrote to the FTC. As members of the Congressional Bi-Partisan Privacy Caucus, we are interested in any actions the FTC has taken or plans to take to investigate whether Google has violated the terms of its consent agreement, they added.

Meanwhile, Google has said the report mischaracterizes the efforts of the company. But the company admitted that a glitch accidentally allowed Google cookies to be set on Safari and promised a fix. Google has started removing the advertising cookies from Safari browsers, according to a statement of Rachel Whetstone, senior vice president of communications and public policy at the search giant.

Cookies are little bits of data collected about the Internet activity of users. They can be useful in instances such as remembering passwords and settings on sites that the user will be surfing on a regular basis. At the same time they also raise concerns about targeted advertising and how much data is really collected.

As noted by Mayer in his study, popular Web browsers provide the option to block third-party cookies, but Apple's Safari browser is unique in that it blocks third-party cookies by default on the iPhone, iPad, iPod touch and Macs.

The study named three other companies, namely, Vibrant Media Inc., Media Innovation Group LLC and PointRoll Inc., which also evaded privacy settings.