Do not talk on your cellphone while riding your bike on a busy sidewalk

I'm usually not at all bothered by cell phone use in public places. If a person wants to have a loud chat on the bus, in a cafe, etc., with a real-life person, that's supposed to be OK, but half that chat, i.e. a cell phone conversation, is supposed to be a major disturbance? A mostly-takeout cafe in Hyde Park has a sign admonishing its customers not to use cellphones while on line, likening cellphone use while waiting for coffee to cellphone use while driving. This is absurd and gratiutously obnoxious on the part of whoever put up and approved that sign.

But, along with "while in class" and "while driving," another category has to be added to the "do not use cellphone under these circumstances" list: Do not talk on your cellphone while riding your bike on a busy sidewalk. Even without applying Kant's categorical imperative, the negative implications of such an action are obvious. The person I just saw doing this was swerving like there's no tomorrow, and has probably at least run over a squirrel at the time of my writing this post.