To say it is a disturbing movie was, for me, putting it lightly.
I think I have seen it two and a half times (the half bit was the first time I saw it, I couldn't watch it all the way through

)
The most disturbing bit for me was how the authorities all came round to supporting Alex in the end, forgetting the anguish and hurt he caused to all his victims.
What an out and out nutter, if he were a tiger in the same vein, loved going on killing sprees, he would have been shot on sight.
Clever film, totally psychological for the viewer. On a purely base level however, I would so loved to have smacked Alex right in the gob.