The earliest of these efforts began soon after the GPL was written by

Richard M.~Stallman (RMS) in 1989, and consisted of informal community efforts,

often in public Usenet discussions.\footnote{One example is the public

  outcry over NeXT's attempt to make the Objective-C front-end to GCC

  proprietary.  RMS, in fact, handled this enforcement action personally and

  the Objective-C front-end is still part of upstream GCC today.}  Over the next decade, the Free Software Foundation (FSF),

which holds copyrights in many GNU programs, was the only visible entity

actively enforcing its GPL'd copyrights on behalf of the software freedom

community.

FSF's enforcement

was generally a private process; the FSF contacted violators

confidentially and helped them to comply with the license.  Most

violations were pursued this way until the early 2000's.

By that time, Linux-based systems such as GNU/Linux and BusyBox/Linux had become very common, particularly in

embedded devices such as wireless routers.  During this period, public

ridicule of violators in the press and on Internet fora supplemented

ongoing private enforcement and increased pressure on businesses to

comply.  In 2003, the FSF formalized its efforts into the GPL Compliance

Lab, increased the volume of enforcement, and built community coalitions

to encourage copyright holders to together settle amicably with violators.

Beginning in 2004, Harald Welte took a more organized public enforcement

approach and launched \href{http://gpl-violations.org/}{gpl-violations.org}, a website and mailing

list for collecting reports of GPL violations.  On the basis of these

formal legal action.  Harald earns the permanent fame as the first copyright

holder to bring legal action in a court regarding GPL compliance.

In 2007, two copyright holders in BusyBox, in conjunction with the

Software Freedom Conservancy (``Conservancy''), filed the first copyright infringement lawsuit

based on a violation of the GPL\@ in the USA. While  lawsuits are of course

quite public, the vast majority of Conservancy's enforcement actions 

are resolved privately via

cooperative communications with violators.  As both FSF and Conservancy have worked to bring

individual companies into compliance, both organizations have encountered numerous

violations resulting from preventable problems such as inadequate

attention to licensing of upstream software, misconceptions about the

GPL's terms, and poor communication between software developers and their

management.  This document highlights these problems and describe

best practices to encourage corporate Free Software users to reevaluate their

approach to GPL'd software and avoid future violations.

Both FSF and Conservancy continue GPL enforcement and compliance efforts

for software under the GPL, the GNU Lesser

Public License (LGPL) and other copyleft licenses.  In doing so, both organizations have

found that most violations stem from a few common, avoidable mistakes.  All copyleft advocates  hope to educate the community of

commercial distributors, redistributors, and resellers on how to avoid

violations in the first place, and to respond adequately and appropriately

when a violation occurs.

practices to ensure that you are aware of what software is in your devices

can only improve your general business processes.  You should ask a clear

list of questions of all your upstream providers and make sure the answers

are complete and accurate.  The following are examples of questions you

should ask:

\begin{itemize}

\item What are all the licenses that cover the software in this device?

\item From which upstream vendors, be they companies or individuals, did

  \emph{you} receive your software before distributing it to us?

\item What are your GPL compliance procedures?

\item If there is GPL'd software in your distribution, we will be

  redistributors of this GPL'd software.  What mechanisms do you have in

  place to aid us with compliance?

\item If we follow your recommended compliance procedures, will you

  formally indemnify us in case we are nonetheless found to be in

  violation of the GPL?

\end{itemize}

escalated because of petty finger-pointing between the distributor and its

upstream.  In our experience, agreements regarding GPL compliance issues

and procedures are rarely negotiated up front.  However, when they are,

violations are resolved much more smoothly (at least from the point of

view of the redistributor).

Consider the cost of potential violations in your acquisition process.

Using Free Software allows software vendors to reduce costs significantly, but be

wary of vendors who have done so without regard for the licenses.  If your

vendor's costs seem ``too good to be true,'' you may ultimately bear the

burden of the vendor's inattention to GPL compliance.  Ask the right

questions, demand an account of your vendors' compliance procedures, and

seek indemnity from them.

In particular, any time your vendor incorporates copylefted software, you

\textit{must} exercise your own rights as a user to request CCS for all the

copylefted programs that your suppliers provided to you.  Furthermore, you

must ensure that CCS is correct and adequate yourself.  Good vendors should

help you do this, and make it easy.  If those vendors cannot, pick a

different vendor before proceeding with the product. 

\section{Mergers and Acquisitions}

Often, larger companies often encounter copyleft licensing during a Mergers