Occupy Wall Street activists are accusing Yahoo of blocking emails that includes the web address of the protest "occupywallstreet.org".

Autoreply emails from Yahoo say: “Your message was not sent. Suspicious activity has been detected on your account. To protect your account and our users, your message has not been sent. If this error continues, please contact Yahoo! Customer Care for further help. We apologize for the inconvenience.”

The videos below from infoplanet.com show the error messages, and show users successfully sending emails from a different address.

Yahoo has apologized and fixed the problem, claiming the problem was the result of a "false positive" spam filter.

Check out pictures from Saturday's protests >