Oh boy. As if the scandal around Uber's threats to monitor and smear critics in the media weren't serious enough. A few minutes ago, Senator Al Franken published a letter to CEO Travis Kalanick demanding an explanation of the company's policies around user data and how that data might be used to attack Pando's Sarah Lacy and other journalists.

The letter begins:

Dear Mr Kalanick:

I am writing in regard to reports of recent comments and actions by top Uber executives concerning journalists. The reports suggest a troubling disregard for customers' privacy including the need to protect their sensitive geolocation data. The involvement of Senator Franken, who is Chairman of the Senate Subcommittee on Privacy, Technology, and the Law, marks a significant escalation in Uber's woes. What previously was a major PR scandal just potentially became a significant legal and political crisis as well.

Certainly one thing is clear: This story is not going away.

Here's the full letter: