Impressions of Diigo

I felt like having a print page where you can freely highlight sentences, add notes and making comments. I think it is useful to be able to modify a web page, which normally can be only read, in a way  more similar to a Word document rather than to a fixed HTML page. However, when I opened an article in PDF format, the "highlight" function was disabled, thus reducing the utility of this tool for clinicians and researchers that heavily rely on e-journals. Also, when looking at the "bookmark" function, I was given the total number of people that had bookmarked that page before with even the exact date of the first one... Frankly, some information that I was not very interested in.