I would be interested in licensing all of my posts, and comments (or any other applicable user-created content) under CC BY-SA 4.0. Is this legally feesible? How would one go about this properly? Is it enough to just state in a bio something like “All of this users posts are licensed under CC BY-SA 4.0”, or would I also have to add “This work is licensed under CC BY-SA 4.0” to the end of every post, and comment that I make?
IANAL but as I understand it, you license your work to someone who has asked to use it. That’s when you negotiate the terms.
Otherwise, you have an automatic exclusive copyright on anything you make, including supermarket lists or doodles on napkins.
Those assholes who aggregate reddit posts are in serial violation of this.