The Electronic Freedom Foundation, along with sponsors including the Consumer Electronics Association, has created the Trolling Effects project to help companies defend against troll.  The Trolling Effects website houses a database of troll demand letters.  It has the opportunity to become a valuable tool for shedding light on patent trolls.  If companies begin to send their letters, a retailer will be able to go the site after receiving a demand letter and get some sense of the scope and seriousness of the troll.  Of course, it will only be as good as the letters that are sent to the site.  So, it will be critical for Trolling Effects to start getting the letters. 

There will be a tension for retailers because sending your letter to Trolling Effects could expose you to the troll as having sent the letter.  And some trolls may retaliate by filing suit more quickly than they otherwise would have or increasing settlement demands.  At a minimum, if I were sending demand letters Trolling Effects, I would redact any identifying information.  Of course, that does not necessarily protect the letter from a subpoena, but if you do the redaction yourself and make sure it is permanent, even that should be relatively safe.