Basically a good idea but it was a mistake to share it here. There are people who can implement this (either by using their own talent or a team of people) on the forums so you gave them a free idea and there's nothing to do about it if they decide to implement the idea (even without crediting you).
If you are going to do this by yourself you must be ready to hire a team of programmers who work on this 24/7 + support people, rent an EXTREMELY expensive hosting plan (your idea in its current form requires huge bandwidth and reliable dedicated hosting). As you said you will also face big privacy problems because it's not wise to let everyone know where you live and the list goes on...
BUT, don't let me stop you or discourage you. The idea is good and you sure have a great imagination. As someone else already said you should start with a little bit smaller plan and then the idea might be achievable some day. I wish you best of luck with the project and let's hope no-one steals it from you!