User blog comment:Semanticdrifter/Updates to COPPA/@comment-1715389-20130701205958/@comment-413936-20130702234713

The main thing involved is IP addresses being included in personal info. IP is also connected to location info in many cases. Also, for users under 13, wikia currently have no real way not to involve IP in identifying one anon from another (and that every editor has IP info made available to collection by wikia).

From what I understand, this doesn't actually "block" the IP so much as it requires the individual sign in to edit. So it wouldn't ban the IP from signing into an account.

With regard to spam and trolls, this is really more of a beneficial side-effect. I admin at a number of wikis, and probably about 80 - 90% of the vandalism does seem to come from anons. While it may curb vandalism, that really isn't the legal issue.