Sylvie Nelson's border crossings are anything but routine. Customs agents sometimes order her out of her car. Twice, they handcuffed her in front of her young children. Once, agents swarmed her car and handcuffed her husband, too.

She tells them: It's not me you want, it's a man with the same birth date and a similar name. Agents always confirm that and let her go.

Then it happens again. And again.