The lawyer who filed the motion to seize the ship is from Mississippi and claims they did it to 'get Carnival's attention', so I doubt it will be a common thing happening. He likely found some little part of the maritime law which allowed it and ran with it, and the magistrate was backed into a corner. Another report
Meanwhile Carnival is optimistic the ship will sail today.
For those with a Google account, you can read the lawsuit here . It appears that they based the seizure on the fact that Carnival plc and Utopia are not registered corporations in Texas. If they were, the seizure would not have been approved.
John Heald just posted on Facebook that the situation has been resolved and they waiting for the Marshals to pack up and leave. I suspect Carnival posted the bond.