This used to be a fax machine "prank"/DoS-- put black construction paper into the hopper, then tape the out end to the in end as it emerges so it forms a "drum"

This used to be a fax machine "prank"/DoS-- put black construction paper into the hopper, then tape the out end to the in end as it emerges so it forms a "drum" of black paper that continuously feeds. Fax that to someone and it ties up the phone line while wasting all the receiver's ink and paper.