The Berkeley-based nonprofit Free History Project has sent a cease-and-desist letter to a right-wing political group which used footage from one of the project’s documentaries in a new ad that tries to tie Barack Obama to 1960s-era radical William Ayers. The letter demands that all broadcasts of the American Issues Project ad, now running in Michigan and Ohio, be halted as a violation of copyright law. San Francisco attorney John Keker wrote the ad’s producers have “willfully violated the Free History Project’s intellectual property rights,” and demanded that they “immediately remove the advertisement from any television, cable network, or other...