They usually show the lock screen, because every manufacturer usually makes their own unique lock screen. Second, if Apple did not patent slide to unlock, and just let someone else patent it (and you know they would) do you think the other companies would not be suing Apple.
They could still patent it and just use it for defensive purposes if someone else sues them first. OR, they could settle for patenting their own specific implementation, to protect themselves, instead of going for such a broad patent.
Sometimes the machines themselves create data, as with a Fitbit exercise tracker or a Nest thermostat. When you work as a coder, you talk about data all the time.
When you create websites, you need to get data out of a database and put them into a Web page. If you're Twitter, tweets are data. If you're the IRS, tax returns are data, broken into fields.