Presidential Candidate Bernie Sanders had to be shielded twice by the U.S. Secret Service while in California ahead of the June 7 Primary, The first attack was in Oakland, then in Modesto by what appeared to be animal rights activists.
YouTube comments suggested the attackers were hired by a Super PAC created by David Brock. After a few searches I found the following:
So far I found nothing that directly links the animal rights group to David Brock, the DNC or any political organization. The last paragraph of the Wall Street Shill article confesses the link is entirely speculation.