Today's letter is F.
Ohhh, I'm so tempted to... Never mind.
I wanted to think of something a little different, so I'm going with FLAME.
Flame, as I'm sure you know, is a slang term meaning a really angry email, blog comment, blog post, etc. (And it's often written in all upper case letters – LIKE THIS – which, as you also know, is the internet's version of yelling.) Why a flame? All bouts of anger are not resolved with physical violence, thankfully. Some are best handled – well, maybe not best handled, but handled – with words.
Thanks for your time.