Who own's reviews?

I am sick of reviews being spread all over the web. Some websites have started to aggregate reviews from all over, but this is just the beginning. It must be more than this. One example is Google offering reviews when you do a search on Google Maps for businesses. They have reviews from Yahoo!, Yelp and etc. These reviews are mostly for restaurants and bars, but other businesses have some reviews too.

I think the worst are product reviews such as appliances and niches not covered well by the likes of Amazon. If I search for the model number of the dishwasher I want to buy I usually get no reviews, similar dishwashers have reviews, but how "similar" are they? Are the main components the exact same? Does that translate into the same performance?

So who actually owns the reviews? The website someone put them into, probably technically. But, why would someone put out a review unless they want to share it with others? Wouldn't they want the biggest possible audience to see it. They should be in the Public Domain, they should not be privately possessed unless the review or comments are collected by or for the actual company being reviewed.

I would like to see Reviews made into a open source set of data. That way people searching could get a much bigger return on their search. By having them in a standard format everybody could access them. You could do mashups like you can with Google Maps. Make them part of a type of open source wiki of reviews.

I think I am dissuaded at times to leave reviews, because I don't know where to leave them. I usually search for reviews on multiple sites, so which of those should I leave the review on? All of them? Its confusing and frustrating, if there was a way I knew most people searching for a review could find it I would do it that way. So maybe like a wikipedia of reveiws.

It also could be part of an open id so that in someones profile are all the reviews that person has ever written. Those reviews would be "hosted" by the person who wrote them or Google or someone else could facilitate hosting people's review profiles. That way a search would turn up all relevant reviews (as long as criteria for how reviews are setup are followed).