Who is harmed by a "Real Names" policy? This page lists groups of people who are disadvantaged by any policy which bans Pseudonymity and requires so-called "Real names" (more properly, legal names).
Often theses policies attempt to reduce or eliminate the veil behind which online bullying, harrassment, and stalking can occur. However, there are unintended consequences to anti-pseudonymity policies. This article is an attempt to create a comprehensive list of groups of people who are affected by such policies. The cost to these people can be vast, including: Google. Facebook.