User blog comment:Semanticdrifter/Digital Protest Against the FISA Improvements Act/@comment-24170330-20140205005836/@comment-5448890-20140205011418

Fun fact: if the police search your house, they can only use what their warrant was for, and they can only look where the item in question was able to be. So, say, a policeman got a search warrant for a stolen laptop. He comes to your house with the search warrant; you have to let him search. However, let's say you have illegal drugs stashed in your coffee maker. Since a laptop is NOT going to fit in a coffee maker, if the policeman found those drugs there, without having a warrant for them, then he couldn't actually get you in trouble for them.

Source: my mother is going to college for forensic investigation, and that bit of info came from one of her textbooks.