The 'burden of proof' is on the plaintiff, since the defendant is presumed innocent until proven guilty. [=the plaintiff must prove that the defendant is guilty]
The 'tax burden' has been falling increasingly on the middle class. [=middle class people have been paying a greater portion of taxes]
For the rest of his life he 'was burdened' with the knowledge that he had done nothing to help them.
(..) we will take them as fuel. We will build a new portal. And when it is complete, we will bring through all... of the Horde. You dare bring that burden into my war band! Let me go, Blackhand. Draka! Push, little one. Push. (..)2016 Warcraft