Someone parked a domain on my server/IP - should I worry? [duplicate]

It's probably a typo, but I would get in touch with the owner of the domain.

Using a whois tool you will get the Administrative and Technical contact.

You should try to have this fixed because if that domain gets associated with spamming, your IP might end up in black lists.

Most black lists have simple forms that you can fill in order to get out of them but it would be simpler to prevent that from happening...