Isnt it a bit difficult to do though its not like people dont have router firewalls and windows firewalls?
It's easy to get around firewalls. Vital system ports are left unprotected which can allow easy access. However, your IP is most likely dynamic, which means if you shut your modem off (unplug it) for five minutes and plug t back in, you will have a new IP address.
I was wondering what is the worst thing some one could do with an external ip address?
The External IP address will identify your ISP and general (city) geographic area, and even that is not certain. Your personal information, such as your address, is known only to your ISP and they will only release it with proper legal authorization.To find what information is shown to others for your Ip address use GeoLocations tools or visit site like IP-Details.com .
If a hacker wanted to mess with you, they could take your IP and do a port scan on your system/network looking for things to exploit. If you have a good(updated) anti virus program and a good firewall installed you won't have to worry much about that though. If your Ip is dynamic you don't need to worry,the Ip will change if you restart your modem/router (mostly) or over a certain period of time.
I am running a small server for minecraft. My isp says i dont have a static ip but i tried unplugging my router for about an hour and plugging it back in and i still had the same ip and i did the ipconfig release and renew and still have the same ip but i dont really care.