There are ways to work around this such as what SQLite does (public domain + explicit license to anyone who asks):
http://www.sqlite.org/copyright.html
The CC0 is currently under an license-review discussion at the OSI. The CC0 explicitly excludes patent rights from the permission and therefore may not be a great choice for a free software license.
There are ways to work around this such as what SQLite does (public domain + explicit license to anyone who asks): http://www.sqlite.org/copyright.html
and CC0: http://creativecommons.org/choose/zero/