I'm a regulatory lawyer and wish to clear a few things up (obligatory: this isn't legal advice!).
Serving yourself alcohol on a U.S. commercial flight is a regulatory offense, but it is not a crime. 14 C.F.R. § 121.575(a) states that "[n]o person may drink any alcoholic beverage aboard an aircraft unless the certificate holder operating the aircraft has served that beverage to him." Violating this regulation is punishable by a civil penalty (i.e., a fine) of up to $1,100.
49 U.S.C. § 46301.
According to
FAA Order No. 2150.3 at 271, individuals who "drink[] [an] alcoholic beverage not served by [the] carrier" are to be fined the "maximum" penalty (i.e., $1,100).
I do not know how often passengers are actually fined by the FAA for violating 14 C.F.R. § 121.575(a). But it has happened before. In 2010, a Continental Airlines passenger named Clare Elaine Spearing was fined $1,100 for violating § 121.575(a). (Figures it was a PMCO FA who turned the passenger in
!)
Here is an excerpt from the FAA Administrative Law Judge's opinion:
Respondent [Spearing] had purchased a bottle of champagne that she then carried with her aboard the aircraft. Once on board the aircraft, Respondent [Spearing] is alleged to have poured herself a glass of the champagne she had carried on board. A flight attendant subsequently instructed Respondent to refrain from drinking the champagne. Ignoring the flight attendant's request, the complaint says, Respondent proceeded to drink the champagne she had poured.
In the Matter of Clare Elaine Spearing, FAA Docket No. CP10EA0003, DMS No. FAA-2010-0313, 2010 WL 3181341 (Aug. 3, 2010).
So if you bring booze on a plane and serve yourself, realize there's a nonzero possibility you could be fined up to $1,100 by the FAA. If you cannot bear the prospect of paying such a fine, you should probably pay the $7 to UA for their crap cocktails. Whether violating § 121.575(a) is rational or not, well, that's your call!