The reality is that you're using the browser under a certain user profile. If you want to really separate your data from other users using your computer i would suggest icognito sessions or creating different user profiles. If you share your user profile (active user) you expose all this data (bookmarks, extensions, passwords).
I love browserling. We share accounts for our business development team and lite web testing at Pulse. Glad to be one of the 100 paying customers. Keep rocking little guy!
I use it for everything. My notebooks look something like this Receipts (fwd via email receipts/tickets/confirmations), GTD (todos, to read, to buy, etc.), Code (html/js/css/code articles), Pulse News (my Pulse saved stories http://pulse.me), Work (all work related notes), Design (pretty images, design, icons).
New fullscreen mode on OSX makes evernote a joy to use.
