Veteran Democratic Sen. Judith Zaffirini is known by her friends, loved ones and constituents simply as “Z.” But authorities told her sister recently that the symbol, which translates in Spanish to “zeta,” could cause the truck to be mistaken for vehicles belonging to the deadly “Zeta” cartel, based on the Texas-Mexico border.

Late last month, police in downtown Laredo pulled over Zaffirini’s sister, Josie Pappas. The officer pointed to three bumper stickers on the pick-up’s back window. The stickers, bearing the word “Zaffirini,” were applied in a big “Z” formation on the glass of the blue Ford F-150 truck. Pappas said the officer asked her if she had noticed “cars full of men passing me by and staring back” at her car recently. The bewildered Pappas answered, “No.”

The officer told her that in Mexico, the Zetas had taken to wearing the letter “Z” on their clothing and their cars. He advised her it was best to remove the stickers “at this time.”