This site was inspired by the recent Google Spain judgment.
On which we made the following commentary.

In line with this, we produced this site to illustrate a simple right to reply mechanism by which:
a) Individuals can add a comment or response to content contained at a particular URL to indicate that it is inaccurate, incomplete, or not up to date
b) Websites (particularly search engines) that link to others can highlight those links in which an individual has responded

See here for an example.
(We are in the process of developing something more interactive)

This is not commercial service/startup. Rather, we wish to indicate the technical simplicity of such an approach. In practice, such functionality would need to be realised by the major players, ensuring a proper process as to how and when responses can be registered and removed, with design features to prevent abuse.

a cambridge-code.org project