Maybe. It is still not clear. In this case "your basement" consists of information (bits). The 5th protects you from divulging information that would incriminate yourself.

If they want to take your hard drive or take your computer as evidence they can take it by issuing a warrant. They can argue that your encrypted stuff is really dangerous because it is encrypted but I think they shouldn't be able to make you talk and divulge the encrypted info.

Now that is what "I think" should happen. I believe there will occur some high profile case, that will lead to creation of laws that will either force key escrow, ban encryption, or force you to divulge the password under threat of jail time or very high fines.