This, of course, does not make it any better when you fall victim to rogueware and end up with your computer becoming infected but, says Graham Cluley, senior technology consultant with Sophos, the message appears to be sent by automated applications.
"These messages, which have been spreading [on Facebook] since Sunday, invite others to participate in the scheme, however the messages are being sent by rogue applications that users have allowed to access their profiles and post messages to their walls", he said in his security blog posting.
"Facebook users who click on the link advertised by their friends are then asked if they want to 'Allow' this application to access their basic information. Participants who allow this are then redirected to a web page which will earn commission for the spammers behind the scam", he added.
According to Cluley, if you have fallen for this trick, you should not hold your breath waiting for a new iPhone.
"Facebook users need to learn to think before they 'like' and 'share' suspicious pages on Facebook. Just because something appears on a friend's wall, it doesn't mean that it is from a reliable source, and by giving unknown applications access to your Facebook page, you could unknowingly continue to help to spread scams and earn cash for the spammers", he explained.
Sophos says that users impacted by the scam should delete references to the free iPhone scam from their wall, and remove the offending application from their account/application settings.