A technique is disclosed for implementing electronic commerce transactions via a data network. A regulated item selected by a customer is identified. The regulated item may correspond to an item which satisfies predetermined criteria, indicating that the regulated item is prohibited from being purchased by the customer. Action is then taken to prohibit the purchase of the selected item, via the data network, by the customer. According to one embodiment, the action taken to prohibit the purchase of the regulated item is automatically implemented at a server system configured to implement electronic commerce transactions between an on-line merchant and the customer. According to a specific implementation, the predetermined criteria correspond to regulations which restrict sales of the regulated items to persons in a particular jurisdiction based upon certain criteria such as, for example, time of day, day of week, age of the customer, type of product being sold, etc.