Google "COINTELPRO." I watched a documentary on Jimi Hendrix's death called JIMI HENDRIX: THE LAST 24 HOURS. FOIA requests revealed that musicians, Hendrix and Lennon included, were put on government watch lists due to their popularity and influence. Plans were made on how to deal with Hendrix as he got closer to the Black Panthers. Some speculate Hendrix was murdered.

A good doc on Lennon is THE U.S. VS. JOHN LENNON. Speaking out against the government and/or its wars will get you in all kinds of trouble.