User blog comment:Cloak5000/Too many Open Source characters/@comment-67.83.205.190-20130605224247

You're probably safer with Open Source, where the characters have a public license, in the long run. Anybody can be wrong in determining if a work is public domain and any idiot can send a Cease and Desist letter claiming to own Crimebuster. If a character is licensed as CC-BY, though, you fill the attribution requirements and do what you want.

They certainly shouldn't be posted without a link where the license can be confirmed, though.