The Right to Have Rights
If you have a PayPal account, you may have gotten an email from them - they've updated their terms of service to remove your right to participate in a class action lawsuit against them, unless you send a formal and precisely formatted letter to their legal department "opting out" of their removal of your rights.
Public Citizen has designed a template (specifically, a DOCX file) you can add your name/phone/email address to, print, sign, and mail to them. I'm doing it. Don't forget about filling one out for eBay too, due on Nov 9.
There's also a classy "rogues gallery", also done by Public Citizen, that lists other companies that have added these clauses to their terms. Everyone from Papa John's pizza to your local nursing home. Truly grotesque.