Strategies in practical GPL enforcement

Enforcement of copyleft licenses like the GNU GPL has always been a
somewhat controversial topic.  Some people are not in favor of
enforcement at all (but then, why choose the GPL and not a permissive
license?).  Other people have less inhibitions in enforcing the
license.  But then this raises the next questions?  Enforcement using
which strategy?  Enforcement using which methods?  The Linux Kernel
developer community has recently re-fueled that debate on the
ksummit-discuss mailing list.

Ultimately, most projects and developers are looking for the
downstream developers and companies to participate in a collaborative
development model.  The copyleft principle is just a legal "hack" to
codify some part of that based on copyright.  As a result, license
compliance is not an end in itself, but the very bare legal minimum of
what needs to be done when engaging in (particularly
corporate/commercial) re-use of Free Software.

This talk will look at the different (GPL) license enforcement
approaches and present their advantages and disadvantages.