A (mid-20s) friend shares a name with a (70-year-old) ex-IRA member, and has been pulled out of the line for extended interrogation every time he's flown since he was a child because his name triggers anti-terrorism flags.
Last I heard he even had to get a special insert for his passport where the US State department affirms that he is not, in fact, an elderly Irish paramilitant.
The best is when you share a name with a famous criminal, and they don't have a picture of the criminal but do find your linked-in photo ...