Trap-stealing is being fixed in Patch 6.0.3
A new round of 6.0.3 hotfixes are up, including the troublesome trapping-at-the-barn issue.
If you have a barn in your garrison, you may run into, or have run into this problem: trap stealing. As you go out to trap beasts, especially elites for Savage Blood, you've probably run into the nuisance of other players trying to trap the creatures you're trying to trap. This makes collecting Savage Blood a headache that often has to be done very early in the morning or very late in the evening, to avoid other players and the problems that can come with them.
While in the new fixes, it is said that two changes will be made to let trapping a lot less frustrating. First, the spawn rate of elites that can be trapped will be increased, to make these rare creatures a bit less rare -- and thus easier to come by. And more importantly, in order to trap a creature you'll need to have tapped it, which means a random person can't just come by and trap your kills.
Hope these fixes will be live soon.