Preserving evidence:
A company involved in the production of GM crops requested assistance when a group of protestors created a web site.
My involvement:
I made regular backups of the protestors' web site so that the evidence could be preserved for future use if it were deemed that they had overstepped the mark and published illegal content.
As far as I'm aware no legal action was taken against the protestors.
As a general principle it is very important that web content is preserved in a format that is acceptable to the courts. It is very easy for a web site owner to amend the content of a web site which may mean that there is no record of any offensive or illegal content.
In some (but not all) cases, there might be a copy of the Web site in archive.org (also known as The Way Back Machine).