To avoid using someone else's copyright protected images you aren't allowed to use for commercial or even personal use, Google Advanced Image Search has got you covered.
You have more people using one computer and you don't want them to be able to shut it down using a shutdown button on Windows logon screen, this is how you remove it.
If you are a "private" person and don't want your profile picture or name to appear on your friend's feed next to ads you liked, then follow this steps.