reputations Builder - asked me to remove a post

One of my sites is a 5k member site where I got an email from a reputation builder website.
They are not US based, but the site they are defending isn’t a USA company either, but asked me to remove a link to a negative post about their client. I probably would be more inclined to yank the post but they are threatening "legal steps". for whatever that means -
Here are the exact words -
"Please remove this article until July, 14th.
If the article will not be removed, we are forced to proof legal steps."

Overall its just a link saying something like "concerning the internet shop XXXXXXXXXXXXXX. A member of a Danish photo community just published this link at the site: XXXXXXXXXXXXXXXXX It is a very long but it is funny and also educational if you are new to internet shops."
Removed the shop name and the review site. I don’t want the modx guys to get the same thing.

Not really inflammatory - So I guess I need to figure out, does anyone have any opinions on what I should do, if I choose to not yank it, since they did threaten me. Where would I get help for this?

I don’t really know another large group of developers to ask the question to.

I would suggest talking to someone in the legal field as this is more a legal question. If the post has merit or truth to it I would suggest fighting to keep it, but then again personally I would rather avoid legal action...