As a public relations jesture, Winchester ceased sale of Black Talon (BT)several years ago. BT are not banned or illegal in and of themselves. Winchester still makes a law enforcement version of the BT, with continuing technology upgrades. The LE stuff is not available in ordinary commercial channels. The LE product does not have the black bullet nor does it have anything on the packaging harking to "BT".
Some people still buy into the BT alure and are willing to pay extra for something they think is extra effective and possibly banned by big brother. Those are foolish people, but it's also their money to spend.