Brent Ozar has an update on getting the latest version of the Stack Overflow data set:
If you only have a limited amount of bandwidth, you don’t have to keep seeding the database after you get it – I’ve got it hosted on a handful of seedboxes around the world.
As with the original data dump, these are provided under cc-by-sa 4.0 license. That means you are free to share it and adapt it for any purpose, even commercially, but you must attribute it to the original authors (not me):
Click through for those attribution details as well as links to get the demo database in various sizes.