Three of Uber's prominent board members have stepped down in the last two months. : Two of Uber's prominent board members are stepping down from the company's board of directors, according to filings with the US Securities and Exchange Commission on Wednesday evening: entrepreneur Arianna Huffington and Matt Cohler, a general partner at venture capital firm Benchmark. Huffington also tweeted the news, saying her decision came about because of her increasing commitments as CEO of Thrive, the health and wellness company she founded. "I will no longer be able to give my board duties the attention they deserve," she said.