I wonder why more sites don't allow you to create a second read only set of credentials for your account. This would solve a lot of trust issues when using a se

I wonder why more sites don't allow you to create a second read only set of credentials for your account. This would solve a lot of trust issues when using a service like this or say for online banking services like Mint. If you want to stream Netflix/Amazon from an insecure computer would be another use case.