Who pays the hosting fees?
"Requiring the published results of taxpayer-funded research to be posted on the Internet"
I'm just pointing out that requiring it to be posted on the internet requires someone to host it.
Open Access journals like PLoS are usually paid by the institute who wants to publish, it costs around $2000-$3000 per paper. In a lot of cases, this cost is carried by a OA-policy or a university's grant for OA-related costs.
If this policy is successful, I guess the tax-payer will carry these costs.