The problem I have with some forums is that they don't give specific examples, but one such forum has enough of a member base to take "hear say" as almost factual. I personally hate reporting on threads that I can not verify or do not verify with my own tests but here is one of those times that I will.
A thread named How can cloaked sites be ranking well at Google? over at WebmasterWorld discusses how recently people have been seeing cloaked sites 'polluting' the Google results.
The thread begins as follows:
What I don't understand is, that if their algorithm is so brilliant how come cloaked sites (the pages which are fed to the crawlers) have poor inbound links, low quality content, almost non-existent internal linking structure and yet they rank at the top? In my opinion, the pages that the cloaks feed to crawlers shouldn't rank highly even if they WERE the actual pages users were seeing!
To me it sounds like either these sites are ranking for non-competitive keywords, or they have inbound links with rich keyword anchor text from other cloaked backs, or Google doesn't care about anchor text. Which one sounds best to you?