The NRA is 4.3 million Americans who care enough about their rights to put their hard-earned money to work (via dues) protecting those rights.

Whenever you read "NRA", substitute "4.3 million American citizens" to give the statement a little context.

Congress are "slaves to 4.3 million American citizens". That sounds pretty great to me!

From the paper (p. 15):
"The capture radius r_c is frequently different from the Schwarzschild radius R, and depends
on the size and state of motion of the black hole, as we"ll as on properties of the surrounding
medium."