I've read a number of reports on the subject of pagejacking that appear to indicate that some search engines will favor the pagejacked page over the original one to the point that the original page will be dropped from the SERPs altogether. (taming the beast)

Pagejacking has been around since the 1990s, acting as one of many black hat marketing methods developed in the internet’s formative years. (WestHost Blog)

An Australian company is at the centre of investigations by the FBI, US Federal Trade Commission and the Australian Competition and Consumer Commission (ACCC), following reports of what has been dubbed "pagejacking" and "mousetrapping". (PC World)