Suppose you were at a cocktail party, and someone approached you wearing a strange-looking pair of glasses, one side of which had a thick aluminum frame. Then you notice there were no lenses on those glasses. Would you know from the outset that the person approaching was wearing Google Glass?

Perhaps more important, would you know that the person approaching you would be able to identify you by facial recognition, and by the time they walked up to you, they would know your name, your job, where you lived and how much you make? And would you know that your conversation was being recorded and that your photo, or whatever the wearer was looking at, could be posted online?

And if you did know, what would you do? Unless you know the full capabilities of Google's Glass project, you'd be hard-pressed to know. And if you didn't, how would you know to ask the person wearing the Google Glass headset not to record you? Chances are you wouldn't.

And even if you did know what Glass is, you might not be able to tell whether you were being recorded, whether the wearer was taking photos of you and what else the wearer was doing with the Glass headset. Worse, suppose the Glass-wearer were to show up someplace private, such as at your home, or in a restroom? Sounds creepy, doesn't it?

It sounded creepy to some members of Congress, too. On May 16, the Bi-partisan Congressional Privacy Caucus sent a letter to Google CEO Larry Page asking some pointed questions about how Google planned to ensure that the privacy of users, and more important, non-users, was being protected. The members of the caucus noted a series of stories in the media that had emerged about Google Glass, particularly the ability to find detailed information about a person just by looking at them, and letting Google perform facial recognition and then providing all available information.

The letter noted Google's challenges with privacy in the past, notably the collection of data from private WiFi networks as part of the Street View project for Google Maps. The letter noted that Google had agreed to a payment of $7 million in fines for collecting the WiFi data. The question: What did Google plan to do to ensure that unintentional data collection wouldn't take place?

The document also addressed the protection of people who aren't participants in the Google Glass efforts. For example, it's not legal in some states to photograph or otherwise record people without their permission. The congressmen want to know what safeguards Google was putting into place to guard against the violation of privacy laws.

The letter asked about the use of facial recognition, how the subjects of data collection would be able to ask to see what was collected about them and how a person could opt out of having their data collected. The members of Congress also wanted to know how Google planned to limit information requests for private data and data from users, and whether the Glass device was able to store any data itself.