What can go wrong with composing a method name out of a string?
myObject[filterMethod]() doesn't exist, you could crash your application.
If your application is part of the safety controls for nuclear missile fire control, you could be potentially disabling critical safety controls.
If other software for the controls doesn't account for this crash, you could allow anyone to fire ze missiles.
If someone is having a bad day, they could decide to try to launch the missiles and be surprised they launch.
If they launch the missiles, you could start a nuclear war.
If a nuclear war starts, you could end civilization as we know it.
FOR THE LOVE OF THE CHILDREN CHECK THINGS EXISTS BEFORE ACCESSING THEM!