A hacked account can happen to the best of us, but it's a bit embarrassing when you're an executive of the service in question. Enter Anthony Noto, Chief Financial Officer of Twitter. He's already suffered a "DM fail" -- accidentally tweeting a message instead of sending it privately -- that revealed a possible acquisition in the works, and today his account appears to have been hijacked by a URL spammer (as seen here, but obviously you should not click the links). Usually these things happen when a user clicks on a phishing link and enters their login details on a webpage spoofing the original service, but there are several ways (besides intense vigilance and never clicking on anything, ever) to prevent this.
Other than making sure to use unique passwords for different services and keeping a close watch on what third-party services have access to your account, one of the best forms of protection is by taking advantage of the two-factor authentication setup Twitter offers. It requires a user to verify their login through a mobile app or with a code sent by text message -- no verification, no login, no hack. We don't know if @anthonynoto was using that before, but you should be now -- click here for more instructions on how to set it up.
Update: We asked Twitter about the situation, and a spokesperson responded that "His account was sending spam Tweets. We've locked the account down and deleted the Tweets. There's no indication any account information was accessed."