after the Google penguin almost all webmasters know that they need to focus more on backlinks from pages with page rank 1 and higher. it's almost the only backlinks that have lower risk and good value (best ROI).
this fact have caused a lot of webmasters to generate a fake PR
and sell links from their fake PR
on forums like digitalpoint and worrierforum and maybe this forum also.
how to detect Fake PR
there are some tools that may show you the change of PR
of the domain name, and if the domain name have made a jump from PR2 or lower to high PR
like PR5 or higher, it is a fake PR
you can also see alexa ranking, or the age of the domain, new domain with high PR
is a fake.
how webmasters fake PR
will that is very easy.
the create redirect from their own domain to high PR
domain, and after a few weeks the creat their own index page, their index page will have the PR
of the domain they were redirecting to, untill Google update PR
or sometimes earlier. there are other option that include a hacking or a black hate strategy that could give them a high PR
(usually 5 or 6) for 3 months.
so just be careful