You say you gave the photographer permission to use photos for marketing purposes. Was that part of a formal agreement, and did that formal agreement transfer of copyright to you? If so, you can request that any website posting the photos take them down under the DMCA takedown rules.
Absent an agreement transferring rights, the photographer controls the right to make copies, post the photos, etc. Legally, the photographer can stop others from posting and reproducing the photos although practically, few photographers will do so. (Before digital photos and scanners, wedding photographers exhibited more control. Nowadays, all they can do is blackmail the family by exposing the more embarrassing pix.)
Your problem goes beyond copyright because you're concerned that someone is making false claims regarding the wedding production. Obviously, the more the material is reproduced on websites and blogs, the harder it gets to halt the annoying activity. Legally, you can stop someone from posting false comments that are defamatory (injuring your reputation), invade your privacy, or are used for commercial purposes -- for example, the photographer licensed images of the bride to be used in a magazine advertisement. Since this is a family affair, it's probably not a good idea to pull out the legal guns. The Dear Rich staff (who truly love a good wedding) hopes that this imbroglio does not mar an otherwise pleasant wedding memory.