There is an interesting thread at WebmasterWorld that talks about the fear of linking to third party web sites.
One webmaster knew he had about 3,000 links to his web site, but the site wasn't ranking well. So he built a program to check the source code of those 3,000 links. What he discovered was that about half of those 3,000 links, linked to him with the nofollow attribute added on to those links. So only about half of those links may have counted.
Further more, he said those links are not coming from user generated content sections, but rather real web pages, real articles, with links within the content. Links you and I would have thought would not have been nofollowed.
Only problem is, they seem to be too scared to link to anything anymore without nofollow in the link.
I emailed a dozen of them and only two responded. Both said they were aware that PR is still lost through the nofollow link. Both said "better safe than sorry" somewhere in the email.
Was this the true purpose behind Google introducing the nofollow attribute?
I'd love to see SEOmoz, RavenSEO or other tools run mass reports on this to see this. I believe some may have done so, but it is always interesting to see one webmaster run it on his specific site. It may not tell the story of what most people do out there, but it does share a story of what can happen to you.
Forum discussion at WebmasterWorld.