I have heard of mining before so that is what it is huh? so if one is to be mined how long do they usually borrow your pc power? and can it potentially do more harm than just slowing things down? I had no idea fully about mining glad you shared this great post.
Some websites tend to use your computer power without informing you about that. How long ? That depends on you, how much you stay on that certain website. I personally think they can't do anything else apart from slowing down your PC and basically making your PC parts tired.
Thanks for the feedback = )