Google's Buzz feature could be investigated by US regulators for breaching the privacy of its users when it launched in February.
Buzz allows uses to share real-time updates in a similar way to Twitter. However, Google received a wave of complaints from users concerned that the networking service had been automatically tied to Gmail accounts without their consent.
Google had already selected the Gmail accounts that users would follow based on their most frequent contacts, and made all this information public. The web giant was then forced to tweak the privacy settings and change how much information would be made public.
However, a group of 11 congressmen has written to the Federal Trade Commission (FTC) asking the regulator to investigate how Google will revise its attitude to user privacy, particularly its Gmail policy.
"Without a doubt this technology has made us all more productive, but it has also made it easier for others to invade our personal privacy, and reveal information about us and our families that we choose not to disclose," said the letter to FTC chairman Jon Leibowitz.
The letter also asks for an investigation into how Google uses the information collected through its services for the purposes of online advertising.
Google plans to buy AdMob in the near future, through which it will acquire more personal information on consumers, and the letter urges the FTC to be cautious before it allows the acquisition to go ahead.
"We understand that the Commission is in the process of reviewing Google's acquisition of AdMob, and we urge that the Commission scrutinise how the deal will affect competition and Google's incentives to offer robust consumer privacy protections," said the letter.
The request follows criticism earlier this month from outgoing FTC commissioner Pamela Jones Harbour, who complained that too many social networks are pushing the boundaries when it comes to protecting consumer privacy.
Harbour claimed that it is now common practice for web firms to launch offerings that may infringe on user privacy, and wait to see whether the product sparks a negative reaction before it is withdrawn and modified.
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