As someone who has already profited from Diamonds generosity (Thanks again, man!), i am kind of angry that the dude didn't even ask.

That said, i don't think there is anything to worry here. He does not take credit for the map and/or names AND he even linked the map via your deviantart portfolio, Diamond. So he kind of acknowledges where the map is from.

As a comment (insight into someone's mind who does borrow maps from others, if you will ) : I always think that something like this is the highest art of flattery! I mean think about it : there is someone who thinks your map is so awesome, that he wants to use it for his stories/rpgs.
I myself would never use a map without asking the creator, mind you! Especially if i link to it or even put it up somewhere on the internet. That's just courtesy.
I guess if i just used it off-screen and at my rpg-table, it would be ok even without asking. But puting it up on the internet...just ask the artist....how difficult is that?! Erm...sorry ^^

Why something like this makes me angry? Because guys like that one make it harder for other people (who are polite and use the right way) to get artists to agree to let them use their stuff. I can understand that stuff like this makes some artists more reluctant to share their awesome stuff...and that is a shame...for all concerned.

The above is for non-commercial use...if you want to use it for more than your own home-rpg or your stories-that-you-never-show-to-anyone...that's a totally different matter.

Anyway...that's my two cents. And i don't want to bore you with more ramblings and rants