Riddle me this #4

RIDDLE ME THIS

If you hold me, folks listen; once you lose me, they stop.
Some say I corrupt, and that a great deal of me corrupts absolutely.

Wires carry me to cities, and one storm can cut me off completely.
Knowledge is said to be me, and I'm measured in watts.

Superheroes have me, and presidents hand me over when their term ends.

What am I?