While details of the tool are still scarce, it's a well-known fact that Facebook cooperates with the police, since, like any company, it has to abide by the law. In fact, just a few months ago, Facebook complied with a police subpoena by sending over 62 pages of photos, Wall posts, messages, contacts, and past activity on the site for a murder suspect.
When backing up your Facebook account, you can download all the information to your computer. If you just want to download your photos and videos, you should specify this on the backup page. Posts, photos, videos, comments, likes, phrases, friends, followers, followed, messages, groups, events, profile information, pages, payment history, saved content, places, ads, search history, location history, searches, if you get full back up the entire archive, including the page, login information, and network information is downloaded. You should download Facebook data because you may need it later.