This thing about young folk and protest music is a bit all over the shop and about 12 months after all the other "young folk and protest music" articles (and I hardly think "counter-cultural musical activist of the 1960s and '70s" is the best descrption of Woody Guthrie. Or Bob Dylan, but don't get me started about that) but this:
After the World Trade Centre was removed from the landscape, some US media corporations banned seemingly innocuous tracks such as Imagine by John Lennon and Peace Train by Yusuf Islam (the former Cat Stevens) from their playlists.
is an urban myth.
Oh, I suppose someone somewhere might have done something and individual DJs will always exercise their own judgement (as they should), but as an egregious example of corporate censorship or whatever, it did not happen. Clear Channel as a relentless music homogonising machine has alot to answer for but not this one I don't think.