I just noticed a 6 year old site I visit from time to time has lost all toobar PR. No PR on internal pages either, I know they have been doing a bit of external SEO so I wonder if they have a ban? Site links and rankings are still there but no PR display for 24 hours now?
Sorry I should explain it a little further, last time and the one and only time I had a site banned from memory the toolbar went out slightly before the rankings. It was a couple of years back so I'm not 100% clear. I just find it strange that this well established site has lost all PR, still no change today.
There's plenty of possibilities, including them losing a major source of links, being a member of a bad neighborhood, having serious server problems (out when the bot from Google called), major page design or reorganization, excessive file renaming, using paidlinks, identical title / meta description issues, nocache adopted, ... and there's a few more where they came from.
And, of course, it may be an incoming ban.
Only the page owner has eough info to be sure, but how does it figure on [a unique string of text from the page]?
"a string of text" returns about 7 results, this site has an alexa of about 20k and they are busy branding themselves in a few other countries with the local domain extension so its possible they have duplicated the site in more than one place. I'm also concerned that the company they paid to do SEO has been doing some borderline link work. As things stand they still have rankings so it may be a glitch, I will update this thread when if something happens one way or another.
It may be worth doing a few keyword searches, noting the results, then repeating the exercise in a week or two if things don't look better; changes in ranking will be a much more objective assessment of their progress than the green bar, which is a useful barometer of trends, but a poor measure of events.