Safari Alert on iPod Touch

On my iPod Touch, I got a warning in Safari saying something potentially bad had been detected. "http:// www.safari-online-alert.com". The screen froze and gave an 800-447-8361 number to call. Is this real or am I being scammed? If I'm being scammed how do I delete the warning?

I exited Safari and rebooted the iPod; but, the warning is still there.

Thank you,

PAul