What is sharia and how would Qatari law affect World Cup tourists?

The ball started rolling. The great stars of world football have come to Qatarthe streets of the country have been filled with color and fans, the stadiums are just as splendid as the skyscrapers that surround Doha, the capital, but nothing has been able to stop the criticism and questioning that tarnishes FIFA’s biggest football event.

What is sharia and how would Qatari law affect World Cup tourists?