It is possible at the present time to make Blu ray backups with free tools. DVDFab has a free section called DVDFab HD Decrypter that will continue to function as a ripping and decryption tool even after the trial ends. It works for blu ray and dvds. The only caveat is that it will lag behind the commercial version by 6 to 8 weeks on updates.
DVDFab also has a program called DVDFab Passkey which will work in the background (similar to AnyDVD HD) and break encryption. It is free to download and use while it is still in beta. It doesn't include a ripper as far as I am aware, but you can use it with something like ImgBurn to make a full ISO of the blu ray movie. Mount the ISO in Slysoft's free program called VirtualClone Drive to work with it using other programs.
If you want just the main movie, you can use ClownBD to select the parts you want. You can run Passkey in the background. ClownBD is also free.
Its not hard to do any of that, as long as you don't want or need to do compression of the movie. Burning to a single or double layer Blu ray disk is easy with ImgBurn, but DL blu ray disks are very expensive. Most people will want to compress to fit 25gb single disks, or take out extras to fit that size. Some make backups to single or double layer dvds, though not all blu ray players can handle them.
Look at a free program called BD Rebuilder for compression. Click on the link in my signature for a guide to that program. Quality is excellent by the way...especially when going to 25gb disks.