Low cost carriers (LCCs) market their flights as low cost and so, aim to garner as much additional revenue as possible from ancillary services such as baggage and priority boarding. The airlines therefore encourage purchase of these services by their customers. As a result of this and other practices by airlines, the European Union has introduced legislation to deal with various areas of concern in order to protect the consumer. Airlines have responded to the legal requirement that all optional extras should only presented to the consumer on an 'opt-in' basis by using 'grey' Web design patterns such as the 'must-opt' presentation of optional extras, whereby the user must choose to accept or reject the item before continuing with the interaction. This study examines user perceptions of the level of compliance of two airlines with the relevant European legislation.