Putting these on a Sony reader is ok, of course...that is the reason they are available on ebook...sharing would only be legit if they are 'for your own use'...ie, another computer at home, a second e-reader etc. I looked into this for some text book stuff for my Kindle, and you cannot share a direct download from person to person- however, if it is a free online ebook, sharing the link is ok, since they are available to anyone - just can't download and then pass on...
FYI - I did think that one of the negatives of the SONY is that they will not accept other ebooks ..when looking at the options of both, that was the determining factor for a few friends...- Kindle will accept any eformat. THey would be interested to know that you can get other ebooks online. Will have them look into it...