I'm perplexed when I hear that .net, php, and other programming languages are the best for web development. But they are not sure of its security! For that reason, I am starting this discussion for everyone who can answer my query.
I suppose PHP is popular and easy to develop web systems hence it should be choose. In the other hands, if you want to have more security on the programming language then it depends on your skills to make your systems secure, it don't belong to what language you choose.