The long and short of this discussion is that it is impossible to "block" your IP address. Impossible. Your IP address is your identification on the internet. Without it, you would not be able to access the internet. There are ways of masking it, or making it more difficult to obtain, but there is no way to "block" it completely.
As such, from that IP address, anyone with the proper tools (most commonly, authorities) are able to deduce your exact location with help from your ISP. It is more difficult for "bad people" to do the same thing, though not impossible.
Obviously, there is no such thing as anonymity on the internet. If you keep your activities on the internet on the "up and up" if you will, you'll very likely never have any problems at all. Don't do things you wouldn't want anyone and everyone to know about and there will never be anything to worry about. Too many people these days think that there is some sort of anonymity attached to the internet, but in reality, the actions of people on the internet are just as freely accessible (to those with the right tools, again) as your actions on the street in front of your house. Proper judgement, as with anything, is the key.
--Travis
