Are they half brothers?
On the DC Comics site it states that Martha Wayne went into the witness protection program after she was targeted by a mob hit,
Millionaire Bruce Wayne is just a kid when he watched his parents get gunned down during a mugging in Gotham City. The crime would define his life, as he dedicated himself to becoming the world’s greatest weapon against crime—the Batman. What the world doesn’t know is that Bruce’s mother, Martha Wayne, was the real target for the mob hit the night that Bruce’s parents were murdered. While in the ambulance it was discovered that she was still alive, and the doctors were able to save her. She signed over guardianship of Bruce to the family butler, Alfred Pennyworth, in hopes that the young boy would be protected, and she was put into the Witness Protection Program and sent to Smallville, Kansas—a quiet town where nothing ever happens.
There Martha met and married a nice young man named Jonathan Kent. With a new inability to carry a child due to the bullet wound, Martha and Jonathan were unable to have the baby they so longed for. However, their prayers were answered when out of the sky, a rocket landed in a nearby field as the couple was driving by. There was a small baby in the rocket who they adopted and gave the name Clark Kent, and who would grow up to be Superman!
So by that it would seem that 'Martha Wayne' and 'Martha Kent' are the seem to be the same person, which would make Bruce Wayne and Clark Kent half brothers.
And in the movie Batman vs Superman, we see Batman stop trying to kill Superman after he hears Superman mention "Martha".
I don't know if this holds any significance?
Is this true?