San Mateo-based Videosurf, a venture backed startup developing a video search engine, has been acquired by Microsoft, according to a report today. According to Israeli news site Calcalist, Microsoft paid around $70M for VideoSurf, which develops a visual search engine for videos. No details of the deal have yet been acknowledged by the two companies. Videosurf was backed by Pitango Venture Capital, former U.S. Vice President Al Core, Facebook's Sheryl Sandberg, Dave Goldberg, and Verizon.