"No adware or spamware!" - blatant lies Rated 1 out of 5 stars
It says on their homepage (http://www.diigo.com/tools/toolbar) that this has no adware or spyware, yet the latest version means every single time I go onto Google I get a very annoying, very obtrusive set of adverts, that are certainly caused by this extension (the element's ID has the word diigo in, and disabling the extension means the adverts go away)
I'd recommend you avoid this extension until they resolve this. Going to check out delicious as an alternative, because this is REALLY poor form imo.