They also used to charge an "inactivity fee" if you used less than a certain minimum amount of data in a month, even if you were supposedly on the free plan. That wouldn't be so bad, except that the only mention of it is buried in the middle of a 5,000 word document that isn't even directly linked at any point in the signup process: https://www.freedompop.com/service_plan_terms.htm

It looks like they abandoned the inactivity fee in June 2013, but even so, it left me with a very negative impression of the company.