What is the connection between Credit cards and guns?

The Senate voted 90–5 today to pass new rules on credit card
terms. The House has already passed its own bill, and it looks
like this thing will become law by the weekend. What’s in it? Oh,
you know, limits on raising interest rates and late fees, new rules on notifying customers and signing up people under 21. And in the Senate version, a provision to allow loaded guns in national parks.