There's not many companies that can take a letter and make it its own.
Type "f" in google, and "Facebook" is the first word that it self predicts.
Draw an "f" in a border surrounded by blue and you know exactly what you're seeing.
Spell checker even suggests using a commanding capital when spelling Facebook!
They have well and truly nabbed it.
That said, did I mention I do a daily doodle on my Facebook page?