There's no doubt that Apartheid South Africa was an evil regime.  Anything which treats certain groups as second class citizens is, and I include the dreadful Indian caste system in that.
 
The brutal murdering of white farmers that goes on now receives very little outrage over here.  It's shameful.

I work with a South African who moved over here a few years ago.  Her opinion is that Mandela was no angel and was indeed a terrorist but he didn't have any other option, having tried peaceful means first.

It seems to me to be a very rare occasion in which terrorism was justified.