One of the roles of the TTB’s is to ensure that alcohol beverages in the marketplace are properly labeled and do not mislead consumers. The TTB maintains an “Alcohol Beverage Sampling Program” (ABSP) which is a random survey of products in the marketplace to evaluate the success of the TTB label approval process and to check for non-compliant products which are in the market without receiving a “Compliance of Label Approval” (COLA) from the TTB.
Each year the TTB conducts an ABSP by purchasing products from the marketplace and do a label assessments to determine if each product is in compliance with TTB labeling regulations. Following the label assessment, each product goes to the TTB laboratory to undergo a series of analyses to determine compliance with certain information displayed on the product labels (primarily alcohol content).
The TTB has just released the results of the most recent ABSP. Of 158 malt beverage samples, there were 61 that were found non-compliant in some way. The number one non-compliance was alcohol content being higher than that stated on the label.
For all of the results, you can see the ABSP summery here