Richard Fontana, co-author of the GPLv3 license who works as an open license and patent consultant for Red Hat, has announced plans to change the Fedora project rules to prohibit the inclusion of software shipped under a Creative Commons CC0 license in repositories. The CC0 license implies a waiver of the author's rights and distribution in the public domain, which allows you to distribute, modify and copy the software without any conditions for any purpose.
Uncertainty about software patents is cited as the reason for the CC0 ban. There is a clause in the text of the CC0 license that explicitly states that the license does not affect patent or trademark rights that may be used in the application. The possibility of influence through patents is seen as a potential threat, so licenses that do not explicitly allow the use of patents or do not waive patents are considered non-FOSS.
The ability to host CC0-licensed content that is not associated with code in the repositories will remain. CC0-licensed code packages already hosted in the Fedora repositories may be exempted and allowed to continue shipping. Inclusion of new packages with code supplied under the CC0 license will not be allowed.
Source: opennet.ru