DAN + SHAY wrote an open letter to autograph hounds who follow them around getting them to sign stuff, just so they can sell it on eBay. They’re mostly upset because it gets in the way of real fans who want a souvenir.
They’re asking people who’ve bought something from an eBay seller to contact them, and they’ll hit ’em back with an invite to a meet & greet, or other autographed items.