I just had an 'aha' moment which I should have saw before.
Sometimes I want to be able to pick and work with an object or reference but not move it by accident. I've always used the outliner to disable the selection and at times it gets annoying having to stop and then enable it just when you're in the middle of an operation . I finally noticed the locks besides the N panel Transform info. I can lock it in place and still select it now.
Yep, but sometimes when you have a lot of object you can accidently grab one you didn't want to.I think that's why they added these features for people like me. 8^]