Is there actually anything behind these allegations, or is this the UK's answer to McCarthyism?

Being outside the uk, these stories don't make the press, so I don't get the full story, but I find it hard to believe that there is much in the way of evidence after all this time, unless they were dumb enough to record their activities...

I don't know about McCarthyism, but there's a distinct whiff about the whole thing. It seems to me there's a lot of 'fishing' going on under the guise of investigation. Pull some 70's celeb in, get the details in the papers and wait and see if anyone puts their hand up.

+1 I think that is the only way it seems to be happening. Also attitudes were very different then, and comparing them to today is wrong. I was reading the Tablet edition of the Metro and today Nicholas Parsons was mentioning the attitudes when he presented Sale of the Century with girls in bikinis displaying the items. He said that there is no way that they would do that now.