While the Bluray digital restrictions management system is a lot more crippling than the one preventing users from watching their legally purchased DVDs, it is possible to decode some Bluray discs on Linux using vlc.

First of all, install the required packages as root:

apt install vlc libaacs0 libbluray-bdj libbluray1
mkdir /usr/share/libbluray/
ln -s /usr/share/java/libbluray-0.5.0.jar /usr/share/libbluray/libbluray.jar

The last two lines are there to fix an error you might see on the console when opening a Bluray disc with vlc:

libbluray/bdj/bdj.c:249: libbluray.jar not found.
libbluray/bdj/bdj.c:349: BD-J check: Failed to load libbluray.jar

and is apparently due to a bug in libbluray.

Then, as a user, you must install some AACS decryption keys. The most interesting source at the moment seems to be labDV.com:

mkdir ~/.config/aacs
cd ~/.config/aacs
wget http://www.labdv.com/aacs/KEYDB.cfg

but it is still limited in the range of discs it can decode.