Users can create a whitelist of sites that the system is allowed to track. And Eyebrowse can be turned off for private browsing.
Aside from social and business research, MIT's Karger noted that the shared information could let users' friends know where they're going to be on a given night so they can meet up or let them know you tried a new restaurant or pair of sneakers so they can ask you about it.
"There's the ability to discover what's popular, in a very broad way," he said. "There's collaborative filtering."
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