When some random site throws my pages into an iframe, at least the user sees what I've served, and I at least have some control -- I can break out of it with Javascript, or I could even serve completely different content.

It's a bit different though when the biggest fucking site on the internet joins in.

Why should I be forced to expend bandwidth every time Google decides a page on my server is relevant to a search result? This could double or even triple my bandwidth costs.

> forced

What? Use robots.txt and exclude yourself from the Google index. It's not like they're preloading the first 200 results for obscure searches. If you're one of the top few results for a very active search then I'm sure someone else is more than willing to take over if you can't handle the load.

If you're worried about Google being a bad web citizen, they've already said that they only use prerendering for the tom search result, and only if they think it has a very high probability of being clicked. (Based on my limited testing, this only ever seems to happen with navigational searches.) So you'd be spending that bandwidth anyway, and your users are getting a better experience out of it.

If you're worried about the technology itself being abused to DDOS people, I don't see how it enables any attack methods that didn't already exist.

If it is as you say, only the #1 result for searches that have a high probability of it being clicked, then it's generally fine with me. If they were blindly pre-loading the first few results, I'd have a problem.

I guess I should give Google more credit, and assume they're not idiots.

Yes, heaven forbid Google sends traffic to your site from people who might find it relevant.

Traffic from people who don't end up viewing the page aren't "people who might find it relevant".

Well thinking of it like an iFrame isn't really accurate because you can bust your site out of one fairly easily.