I'm not so sure about this. Wouldn't this just lead to censorship?

I've seen this implemented on sites like Flickr and YouTube, where if you post a video or a photo you can delete comments underneath it that you don't like.

Does it work? The comments on YouTube are still pretty much the worst comments I've ever seen on the internet. Whenever my faith in humanity grows too strong , I can go read YouTube comments.

On Flickr, there's a "block" option, which prevents people from posting comments on any of your photos, and people use that a lot, because after all, once you delete a comment it's pretty easy for someone to just repost it again.

Rereading this I'm not sure if the other reviewers are referring to off-topic reviews left on items on your list, or off-topic comments left on your review. These are two different issues. For the former, there's the Flag a Review feature, where you can mark a review as Off-Topic.

We don't currently have a good solution for off-topic comments on a person's review, but I'm hesitant to say that allowing the review owner to simply delete any comment they don't like would solve the problem. I'm curious what other people think about this.

On some sites like Digg, you can down-vote a comment, so below a certain threshold, it doesn't show up by default, but it's still there. On other sites like BoingBoing, a moderator will "disemvowel" comments that they think are putrid, which leaves the comment there but makes it hard to read. Another option might be expanding the use of the flag feature so that users can flag comments.