DES MOINES, Iowa—President Barack Obama is planning an outdoor rally here on Monday, but one store within the event's security zone is taking a stand against Secret Service searches inside the shop.

A sign on the window of Raygun, a clothing store that sells quirky T-shirts, tells Secret Service agents who intend to "sweep" the premises before Obama's speech that it does "not consent" to any searches. The sign also added a little humor, too: "It's not that there's anything illegal in here, we just employ several Colombian prostitutes and don't want to tempt you guys," the sign reads, a reference to news reports earlier this year about some agents who had solicited prostitutes in South America.

The Obama campaign was not amused. A store clerk told Yahoo News that the sign went up Monday morning, and Obama staffers have asked for its removal. The store is refusing.

Update 6:45 PM: The sign was removed from the window before Obama's rally started Monday evening.