I clicked on a link in Stats, that referenced activity from "opensocial.googleusercontent.com", and got "Page not found". Is somebody hacking my blog?and
What is "opensocial.googleusercontent.com"? I see that URL a lot, in my visitor logs!Fortunately, this is a slightly less mysterious and sinister story.
Take a look at the Following community on your blog, or any other blog that interests you. See the icons, of the Followers? Click on one, and watch the contents of the browser status display (generally, the lower left border of the browser window), closely. As the large white popup window opens up, in the middle of your browser, you'll see "opensocial.googleusercontent.com" mentioned in the status display, briefly.
The popup window, with the Followers profile - including a list of blogs owned and / or Followed - is hosted from "opensocial.googleusercontent.com". That's the purpose of Following - giving people a chance to surf from blog to blog, using personal recommendations (lists of Followed and owned blogs) from the Followers and blog owners.
When you surf blogs using Following, you're opening these temporary popup windows, and you're generating temporary pages displaying the profiles of the Followers. When you click on a URL that looks interesting, to check out somebody's blog, you're generating an inclick ("referer entry"), from "opensocial.googleusercontent.com", in the Stats / visitor log for that blog.
When you close the popup window, that temporary URL goes away. Separately, and later, when you examine your visitor log, you see these "opensocial.googleusercontent.com" referer URLs, you click on one, and you get "Page not found", it's because that was a temporary page, hosting the popup window. That page existed in cache, on the computer owned by someone who just visited your blog - and it's long gone by the time you view your Stats display.
The bottom line is that these mysterious log entries mentioning "opensocial.googleusercontent.com" are the result of activity from Followers, visiting your blog. It's good to worry about hacking - just don't worry needlessly, from seeing "opensocial.googleusercontent.com" in your visitor logs. Get back to work, on your blog.