Comment 26 for bug 48734

Encryption also adds significant overhead to file read / writes which people
on slower computers can't really afford. As for booting from a USB drive,
there's a huge difference between a family member (if we're assuming that
usage scenario) doing a computer wide search and turning up a private email
or diary entry or something, and someone maliciously booting off a USB-drive
expressly to gain access to your files. Finally, if you're already offering
a psuedo-fix option during the installation process, why not add a real
check box that says
"Allow all users view the contents of my home directory."

I think you'd be surprised by how many people uncheck that.