Yes, that's something Twitter is pretty good at. E-mailing random people feels more intrusive to me, and blog comments or similar channels aren't always available or appropriate (although Twitter certainly is to blame for at least some of that)
Exactly this. People are trying to sway the discussion with "single mother" and "mexican" implying that "people of color who make unfortunate choices" should somehow be exempt from the uniform and fair application of laws.
ICIM: I'm a "person of color who's made a lot of unfortunate choices" ;=D