A nice little find by Niall Donegan who discusses Unison.ie cloaking:
A prime example of this is Unison.ie. When searching for current Irish news it usually ranks fairly high on Google, however all the pages require you register first before you view them. The registration gives no advantage to people like me who just want to a quick look at the latest news. I suspect that I’m not alone and that lots of people will just go back and look for another site.