Linus Torvalds has... let's just call it a "reputation" for being blunt. Submit a code change to the Linux Kernel that he doesn't care for? You're going to hear about it, possibly in some pretty colorful language. Here are some quotes to give you a taste of his style (the more colorful quotes have been left out so as not to offend...everyone).
"I hope I won't end up having to hunt you all down and kill you in your sleep."
"Standards are paper. I use paper to wipe my butt every day. That's how much that paper is worth."
"If you want me to 'act professional,' I can tell you that I'm not interested. I'm sitting in my home office wearing a bathrobe."