While I'm learning to love the new feature in Google Reader that allows you to add notes to your Shared Items feed, a very salient observation was made this evening by Ryan S. over at Duff's Device:
The (current) top item in my Shared Items feed shows that you can alter the text of any article, I couldn't find the permalink in my Shared Items Feed. This could lead to misleading people by changing the content, or even adding more content. It could end up with me not being able to trust content from shared items anymore. The article appears in my shared items feed with the article changed with the text I included. Note that you can alter full html markup of the article, potentially leading to other sorts of attacks. Hopefully Google changes this back soon, I'm content with them continuing to post the full article in my Shared Items feed.
The feature was written up by Adam Ostrow here at Mashable earlier this week, and to a great reception by him as well as many other bloggers out there who are fans of Google Reader. Unfortunately, with the ability to modify HTML code within the notes feature, it does potentially leave an open door to attacks on user machines.