Insofar as the majority of that traffic is likely illegal (in terms of sharing pirated property) I would not consider it useful.
* defend myself
* rob you
* murder you very effectively
* enjoy target shooting
* hunt wild game
* provide peace of mind in troubled times when law and order break down
The fewer guns there are per capita, the more useful they become for criminals. They are so useful, in fact, that people will spend a lot of money and subject themselves to costly and invasive regulations just to buy one gun. If no one found them useful, no one would find it necessary to ban them.
Perhaps you meant (and people should have charitably interpreted you as meaning) "I would consider it to have no legitimate uses" or "... no uses worth supporting".