I used to get angry, then I got suspended, so now I just go 'pffft' and walk away from the thread. Simple. Everyone is entitled to think and type what they wish on here within reason, if we all agreed then the site would be a boring place indeed.
I do however, keep a mental note of people who have riled me in the past (only one so far) and if I see them contributing to a thread, I keep well away from it.