It's the form of "f" used in italics, only un-italicized.
I think part of my brain keeps thinking it's the italic "f" in math notation "f(x)" and then gets confused to find it as part of a regular non-italic word.
Or it might be the fact that our brain relies heavily on word shape for fast reading, which is heavily dependent on the presence or absence of ascenders and descenders in lowercase, so adding a descender on a letter than shouldn't have one totally breaks our natural pattern recognition.
In any case, I've never come across it in any typeface before in my whole life. Now I'm starting to see why. :)
Removing the top pixels from characters greatly reduces readability, which is not as significant if you remove the bottom ones. Then why does this happen? Any ideas?
For now, at least, browsers still allow the end users to configure this stuff, so let's give them that opportunity.
f(ingerprint)