Do you use the free, online service "Instapaper"? If you don't, you might want to. It's a great way to manage the loads of information the internet throws at us each day. It's simple: when you have an Instapaper account, you can put a shortcut in your browser bookmarks. Whenever you come upon an article you'd like to read but don't have time for at the moment, you click the shortcut and it saves the article to your Instapaper account. You can then access it, even without an internet connection.
Therefore when the FBI confiscated (or in the words of Instapaper founder Marco Arment, "stole") the servers on which Instapaper stores its users information and content, it was tantamount to the FBI peeking into your library records without a warrant. Except in this case, it also got your email address, connected to a taste of your online reading habits.
What's the problem here? Well, the FBI wasn't after Instapaper at all, warrant or no. It busted into a DigitalOne building to confiscate servers belonging to another customer, but it took those servers nearby, too, just in case.
As a result, it's possible that the FBI now has my email and Instapaper articles, as well as those belonging to hundreds of other Instapaper users. In a sad statement on the rule of law and the FBI's proven disregard for the privacy rights of Americans, Marco Arment worried that even if the FBI never gave the server back (it did), he would have little legal recourse.
See his update to learn more about what happened.