Slashdot reports Yahoo seemed to be censoring e-mails about Wall Street protests:
"People trying to email information about the Wall Street protests on Monday using Yahoo mail, found themselves on the receiving end of messages from Yahoo claiming 'suspicious activity'. ThinkProgress.org has a YouTube video of users trying to send emails that mention the 'OccupyWallSt.org' web site, which seemed to be the magic phrase to get your email blocked. Via Twitter, Yahoo announced the blockage was now fixed, but 'there may be residual delays.'"
The company later apologized on Twitter for blocking ‘occupywallst.org’, claiming the domain was accidentally caught by their spam filters.