encrypted /tmp? encrypted home dir but remotely rebootable?

[Bob Smith]

>     Bob you have already gone way to far with with your encrypted home 
> directory. Take all that stuff off and use your password. I have used 
> ssh for years and never had a problem.
> 
>     To get on your computer a person needs to know the IP of your 
> system, your home name and password.
> 
>     Not sure how you turn on your computer from the remote location but 
> new computers seem to be made to do that.

What if someone steals your computer and sticks the hard drive in
another machine (with your financial records, personal e-mail, and so
on)?