The issue of data collection is an important one in online privacy, particularly as it applies to ad networks. This issue is especially contentious in the context of Do Not Track mechanisms. A number of browsers – such as Safari, Internet Explorer, and Firefox – have mechanisms that permit consumers to instruct websites not to track their activities across the web. The FTC has said on numerous occasions, though, that an effective Do Not Track system should go beyond opting consumers out of receiving targeted advertisements; it should opt them out of the collection of behavioral data for all purposes, unless the purpose is consistent with the context of the interaction (e.g., to prevent click-fraud). Such sentiments were expressed in the FTC’s Privacy Report, as well as its testimony before Congress.

Last month, FTC Commissioner Julie Brill delivered a speech at the State of the Net West conference in San Francisco, calling on ad networks to spell out why they say they must collect data from consumers who do not wish to be tracked. "On numerous occasions, the FTC and other stakeholders have asked the advertising networks for specific market research and product improvement uses that require retention of linkable consumer data. The advertising networks are the only ones who can make the case for such use; without input from them it will be hard to see how such uses can be justified when a consumer has opted out of tracking." In that same speech, Commissioner Brill cited to a recent study by the Pew Research Center on privacy concerns with mobile devices. That study noted that 54 percent of app users have decided to not install an app after they discovered how much personal information they would need to share in order to use it, and that 30 percent of app users have uninstalled an app that was already on their phone because they learned it was collecting personal information that they didn’t wish to share.

Ad networks, and more broadly, all companies that collect data about consumers, should take note of the FTC’s focus on data collection. Data collection efforts should be limited appropriately and be accompanied with accurate disclosures.