you know that Harry was being mind-controlled?

At the very start.

If you would recall earlier they were describing incidents in where similar situations happened, and you can basically put together two and two. 

Plus add that with the fact everyone got the free sim card.

It was fairly obvious something was affecting him the moment he shot that woman. Not just because we knew Valentine had started the test, but because it went against everything his character stood for (which i expect was the point). Once we saw everyone in the church start going ape-shit, coupled with the reports Merlin had spoken about towards the start, the specifics of the situation became pretty clear.

That part really blew me away though. I had a vague idea of what i was getting myself into when i went to see it, but i wasn't expecting an ultra-violent massacre followed by Valentine shooting Harry in the head. The film had some serious balls.

Ya, they really did that well. Also the references to other spy movies/TV of past was amazing cherry on top. However I knew it would have decent amount of violence because of Kick-Ass.

When he shot that racist women. I was expecting a shite movie, but the movie was surprisingly good. I hope they make a sequel

It's done very well at the box office. No reason why it shouldn't.

I can't wait. Excellent movie.

Also the best line from the film (happens to be in that church scene).

"I'm a Catholic whore, and I need to visit my black Jewish boyfriend who works in an abortion clinic. Hail Satan."

Don't know if this was the exact line.

Crappy version of the line  https://www.youtube.com/watch?v=AKtCBmV-wBM

Walk me through your thought process though. I was shocked the moment he shot her in the head because I thought he shot her because she was shouting at him and it was so out of character.

I am just baffled that someone managed to figure out that he was being mind-controlled straightaway. Especially when the SIM cards could have done any number of things like explode or whatever.

It's doing ok. It will go down to the remaining territories to make sure this movie doesn't end up being a flop.

Don't you remember earlier in the film, how they talked about situations where entire camps of people were seemingly destroyed from everyone going to a rage like trance. When they are discussing the original Lancelot's assignment.