Going to Settings, Storage & USB, tap the SD card and you’ve got the option to format as internal. Formatting as internal storage will encrypt and use the SD card as adoptable storage meaning apps have a lot more space to breathe, and if the card is yanked it’s encrypted and can’t be used by anyone else.
While I don’t see much use for this at the moment, I’m sure we’re rapidly approaching the days where a simple “Hello World” app will now be 18 gigabytes with included libraries and then translate into another 20 in ART cache taken.
Also probably useful if you want to make sure any photos you take never will fall into the hands of others.
I’ve got a bit too much data on my card at the moment to play with it, but if anyone has chance to play with it let us know if you see any performance hits.