I'd go for the auto-sign idea too ... I echo the 'honey-flavoured' sentiments, that you can't have a meaningful good without a bad, but when the bad comes from out of nowhere, it means:
a) you don't know where to fire back at :blackeye,
b) you don't know whether you managed to wind the
intended sucker up enough :naughty,
c) you perhaps don't even know WHY

, and in any case,
d) the list of chicken-shits out there just got another entry on the bottom :mute
P.S. Eric, define a side in the following manner (coming from a real-world hardware engineer, rather than a theoretical 'softie'

), and you have your argument for a one-sided circle:
a 'side' is a boundary between 2 areas - this must not necessarily be straight, and in the real world, is never perfectly so: think of the 'side' of a car, monitor, etc. (taking natural tolerances into account, ANY object).