http://www.promom.org/3min/3min_livejournal_may06.html Long Story Short:
Apparently, LJ/Six Apart/LJ Abuse Eric believes breast feeding icons are just as "obscene" as tit-bearing icons in general. Something natural (that's "more baby-head than boob" anyway) is now obscene and shouldn't be used as a default icon. Kinda reminds me of an old icon about swastikas vs breasts.