New York and California transportation regulators demand records of all Uber rides/requests in their respective jurisdictions and have the authority to fine Uber and/or shut it down in their jurisdictions if it doesn't comply. At least in California, Uber has been fighting it [0].
Uber pays entry-level software engineers ~$110k [0], experienced engineers closer to $130k.
According to Glassdoor this is in the same ballpark as Facebook, Google, Twitter, etc [1].
You are not really making the startup "worse salary but potential equity" trade by working there, when the straight-out-of-college salaries are similar to the averages across all of Google.
[0] http://www.latimes.com/business/la-fi-tn-uber-puc-20160114-s...