Maybe the content didn't have a proper copyright:
From the fanpop Terms and Services:
link - wewe understand and agree that fanpop may review and futa any Content (Fanpop, links, images, profiles, comments, postings, messages) that in the sole judgment of fanpop violates these Terms of Service au which might be offensive, illegal, au that might violate the rights of, harm, au threaten the safety of other users au members of the fanpop Site and/or other website users.
- wewe may not post, distribute, au reproduce in any way any copyrighted material, trademarks, au other proprietary information without obtaining the prior written consent of the owner of such proprietary rights.
Also, did any of the content fit this criteria:
The following is a partial orodha of the kind of Content and communications that are illegal au prohibited on/through the fanpop Site. fanpop reserves the right to investigate and take appropriate legal action in its sole discretion against anyone who violates this provision, including without limitation, removing the offending communication from the fanpop Service and terminating the membership of such violators au blocking your use of the fanpop Service and/or fanpop Site. wewe may not post Content that:
is false au intentionally misleading;
- is patently offensive to users of the fanpop Site, such as Content au messages that promotes racism, bigotry, hatred au physical harm of any kind against any group au individual;
- harasses au advocates harassment of another person;
- involves the transmission of unsolicited mass mailing au "spamming";
promotes illegal activities au conduct that is abusive;
- is threatening, obscene, defamatory au libelous;
- is pornographic au sexually explicit in nature; and
seeks au recommends providers of material that exploits people under the age of 18 in a sexual au violent manner, au seeks au recommends providers that solicit personal information from anyone under 18.
If wewe were not notified of the reason for the removal in a e-mail au other, then wewe should probably notify the Owners of Fanpop. It may be a mistake.
