Given what we know about American involvement in the 2002 coup against Chavez and the current instability in the Ukraine it seems likely the CIA etc are involved in this Venezuelan instability too. The latest Snowden files show the NSA is heavily involved in propaganda over the Interent. I'd guess Maduro is telling the truth (just as many government employees and pro-government civilians have been killed as anti-government protesters so I'd guess most of the violence is by agents provocateurs on American payroll).