holy crap guys
how would you feel if someone told you where you ate for breakfast this morning
or what online friends you have on your computer
or what you do in secret
sure, all of that is public and obtainable, but do you really want someone telling other people about it?
if swollow knew his street address and gave it out, that's not just "rough location" or "location of the isp"
that's his dead on address
Just by getting an IP doesn't mean anyone can find out all about that. You get a rough location, IPs can never usually give you an exact address. Most of the time, the town / city is off by a bit, so getting it precise isn't very common.
Of course, some people prefer this undisclosed, but it's not bad if someone does find out. Every single website you go on to might record your IP address, and the Blockland Forums probably has already done that anyway.
It's not going to cause real harm, because it seriously just gives you a rough estimate in terms of location.
To sum it up, some people don't want this information disclosed, and that's fine - it wouldn't be a good idea to annoy them and go against their will. Of course, silently many sites actually record the IP, but some people would trust them. But if someone actually does find out your IP, it's not so bad, they'll just get a rough estimate of where you live and nothing else.