when I play at multiple tables, I am always afraid that my lights will be turned off or the Internet will be turned off and I will lose a lot of money.
That is exactly the same reasons I quit playing multiple tables, things like that do happen, and happen on a regular basis in some parts of the world.
How many times have you been playing a game and suddenly the chip leader starts to sit out, has he taken a coffee break? or gone to the bathroom? No! I would be willing to bet he has power issues or computer issues etc and he is somewhere in the World tearing his hair out, because he cannot get back on-line.
I once finished heads up against one such player and I sat there raising every hand, just to steal the blinds because he was sitting out, What else could I do? He eventually returned to the game but was so low on chips I was calling any all-in with anything I was holding.
Poker is a fun game, but when things happen that are out of your control, you are then helpless, It happened to him and it has happened to me, that is why I always say:-
When the fun Stops, STOP!