Customer group policy has no checks, possibly risky usage

[pladodev]

Hi,
I start to implement Turpentine in my shop when I try this behaviour:

• Start a navigation session
• Create a customer_group cookie (Chrome-> Dev Options -> Application -> Cookie -> customer_group) with a valid ID
• Reload the page...
• Boom... I can see the prices that I'm not able to see like a not logged user.

Same issue if you change the cookie and reload.

In my shop I've no public prices, only logged user with another customer_group can see it.

It's possible to fix with a magento check per session?

Thanks