Lumen (website) - Definition from the Hotspot Shield Glossary

Lumen is an online archive that aims to protect lawful online activity from unfounded legal threats. The archive was created in 2001 by Wendy Seltzer and the EFF (Electronic Frontier Foundation) and allows anyone who has received a “cease and desist” notice, to have that notice reviewed to check its legality and to find out what obligations (if any) the person has regarding the notice.

Historically, there had been many cases where cease and desist notices had been served without due cause or reason, and this was seen to be damaging to the publics freedom of speech. The site has gained mixed reviews; by some it is seen to allow people to subvert copyright infringements, while to others it represents a defense of freedom of speech.