Agreed that you can get them through as long as they fit withing the Freedom Baggie guidelines. I do it all the time because I like to enjoy a nightcap in the hotel room without paying an arm and a leg for Room Service.

As for drinking it on the plane- well, an FA actually has to see you do it, which means they have to be passing through the aisles paying attention to the pax. In Coach class on a typical airline, no worries on that front.