This is the Cato Daily Podcast for Friday, May 6, 2016.

I'm Keelah Brown.

As the field of three-year-olds prepare to run for the roses in Louisville tomorrow,

a Kentucky business continues its

aggressive moves to prevent people from pretending that they're selling

authentic Derby Pies. But what's in a trademark anyway?

Cato Senior Fellow Walter Olson explains.

When companies have trademarks,

and this is a quirk of trademark law that I think a lot of people really don't understand, which is if you're not constantly

asserting that trademark, it can be taking a word, you can lose it. You can lose it. This makes trademark law different from copyright law or

patent law. If you are tolerating the use of your product name in a generic way especially,

that is to stand for the same type of product but made by someone else you may lose it and that

means that many trademark owners who might not want to pay lawyers so much to file so many

take down letters find that the law is itself pressing them to be super aggressive.

Okay, so the example we're noting here just before the first Saturday in May, the home of the

date of the Kentucky Derby is Kearns Kitchen in Louisville, and I happen to know for a fact that there

have been kitchens in Frankfurt, Kentucky, and elsewhere that have advertised the sale of a Derby

Pie. But because of the history of this kitchen producing it, and then they eventually filed for a trademark for Derby Pie, which I believe the actual trademark symbol is pressed into the crust of each of these pies.

They've had to go around and issue these letters.

And I mean, I'm sure that creates a lot of bad blood to be using a name that is essentially

pretty generic as your trademark?

Certainly in the Louisville area they have shut down numerous other food providers who have listed

...