The full letter is included in the article, and the signatures are from three people (representing at least two VC firms). They claim others will be adding their names to the letter in coming days. From the article:
Who signed the request? Shervin Pishevar (Sherpa Capital, although signed as an individual), Ron Burkle (Yucaipa Cos) and Adam Leber (Maverick).
[Edit] According to Crunchbase [1], Sherpa Capital was involved in Series D and Series E funding for Uber, while Adam Leber was an Angel investor. I couldn't find info on Ron Burkle or Yucaipa Cos.
Ron Burkle is a billionaire based in LA who made most of his initial money from grocery stores (A&P). Yucaipa is his personal investing vehicle and has a fairly high profile in the relatively rarified world of private-equity-funds-that-invest-one-very-wealthy-person's-money.
That world is sort of the dark matter flip side of Venture Capital. A firm like Yucaipa doesn't need to blog or tweet -- doesn't need to market itself -- because it never needs to raise money from limited partners, and it's super flexible and agnostic about the kinds of investments it's looking for, time horizons, and how exactly it structures deals.
Thanks for that, fascinating! I searched a bit further and found out he is also co-owner of the Pittsburgh Penguins NHL team. He seems like an intriguing person.
