Originally Posted by ESpen36

It's fine to bring through security as long as the bottles fit in the Kippie bag and each bottle is 3.4oz or less.

Note that it's a violation federal law to consume alcohol on board unless a flight attendant serves it to you.* So, if you wanted to drink your self-provided alcohol, you would need to give the bottles to the FA so that she can pour the alcohol into cups for you. I know that several FTers do so regularly without a problem--though it tends to be in premium cabins where pax want to consume their duty-free purchases, not in coach where pax want to avoid paying $6 a drink.

I imagine it would be easier to find a cooperative FA when traveling up front.

(*In some countries, it's more strict. Under Canadian law, the aircraft operator must provide the alcohol, in addition to serving it. You cannot provide your own for on-board consumption.)