Kali Linux is a Debian-based distribution developed by Offensive Security. This distro was made for ethical hacking and cybersecurity work, not for personal use. It includes password crackers, social engineering tools, and phone number finders. Everything can be done, but only for ethical purposes. I'm not encouraging anyone to attack or harass someone—you have the responsibility for your actions.
NOTE: Let me be straight. Isn't neccesary to use 7.0 version. I use this because it is more fast and can't delay the performance.