While technology gives marketers better ways to keep track of us every day, U.S. Sen. Al Franken says he's looking out for you. On Monday, the Minnesota Democrat released a letter from Silicon Valley-based Euclid, Inc., one of the nation's leading analytics firms, promising to protect consumer privacy and never sell the data in collects to brokers. But Franken said the company's promises don't go far enough. The back-and-forth stems from Franken's campaign to rein in intrusive technologies like smart phone apps that track your every online move through cyber and physical space. Euclid caught his attention last month amid news reports that the company's technology has tracked approximately 50 million Americans through their smartphones without their permission as they go about their daily shopping. According to Franken, Euclid keeps ubiquitous tabs on consumers as they walk through malls, walk past or stores, or move between a store's floors by tracking unique signals transmitted by their smartphones. Unless people visit Euclid's website to opt-out of being tracked, their location is collected without their permission or knowledge. "It's one thing to track someone's shopping habits through a loyalty card or credit card purchase," Franken said in a March 13 statement. "It's another thing entirely to track consumers' movements without their permission as they shop, especially when someone doesn't buy anything or even enter a store." In a letter to Euclid the same day, Franken sought an end to the practice. In a company letter Franken released Monday, Euclid CEO and co-founder Will Smith defended the practice, but made a number of privacy guarantees, such as never linking its tracking data to specific individuals or sharing that information with clients. In Euclid's defense, Smith said the company's technology evens the playing field between online retailers, which get gobs of customer data every day, and bricks-and-mortar stores vying for foot traffic in real time. According to Smith, as a shopper carrying a smart device walks by a retail store, the Euclid sensor at the store recognizes the broadcasted ping, scrambles identification data into what is known as a "hash," discards the address data, and sends only the hashed data to Euclid's servers. "We use this anonymous data to derive aggregated insights about in-store traffic that are shared with the retailer," he said. "The retailer can use these metrics to better understand how staffing, merchandising, and window display changes might affect the number of visitors who enter their store and stay long enough to complete a purchase." But Franken does not appear satisfied with the company's assurances. "I'm pleased that privacy is a priority for Euclid," he said Monday, "but their continued use of opt-out technology underscores the need for Congressional action to protect consumer location privacy." Franken introduced the Location Privacy Protection Act in 2011 to protect consumer privacy by requiring companies to get permission before collecting or sharing consumers' location data. The bill was approved by the Senate Judiciary Committee in December, though many members of the committee expressed deep misgivings about the details, leaving its fate in the full Senate very much in question. Euclid Privacy