Care2 - Provide an Option for People to Dissent from Petitions

Anyone who looks at the Petition Site regularly will see examples of occasions when people have signed petitions in order to have the opportunity to make a comment saying that they disagree. If the petition is one that has attracted a lot of signatures, this makes it difficult to know how many of the signatories really do support the aims of the petition. Another campaigning agency, 38degrees, has a Disqus discussion page for petitions, enabling people to say what they think without signing the actual petition - if they can do it, why not Care2?