example.  

Because copyright controls are usually automatically granted and because, in

some jurisdictions, some copyright controls cannot be waived (See

Section~\ref{non-usa-copyright} for further discussion), many copyright

holders sometimes incorrectly believe a work has been placed in the public

domain.  Second, due to aggressive lobbying by the entertainment industry,

the ``exclusive Right'' of copyright, that was supposed to only exist for

``Limited Times'' according to the USA Constitution, appears to be infinite:

simply purchased on the installment plan rather than in whole.  Thus, we must

assume no works of software will fall into the public domain merely due to

the passage of time.

disclaimers of copyright or public domain dedications we see in the

Free Software world would be interpreted by courts as copyright

abandonment, leading to a situation in which the user effectively receives a

maximum grant of copyright freedoms, similar to a maximally-permissive

Free Software license.

The best example of software known to truly be in the public domain is software

\href{http://www.law.cornell.edu/uscode/text/17/105}{17 USC 101 \S~105}, all

\subsection{Why Copyright Free Software?}

If simply disclaiming copyright on software yields Free Software, then it

stands to reason that putting software into the public domain is the

easiest and most straightforward way to produce Free Software. Indeed,

some major Free Software projects have chosen this method for making their

software Free. However, most of the Free Software in existence \emph{is}

copyrighted. In most cases (particularly in those of FSF and the GNU

Project), this was done due to very careful planning.

Software released into the public domain does grant freedom to those users