The 13.560 band is shared among a number of radio services. Among other things, FCC Part 15 govern low power hobby communications, RFID, remote control, wireless charging devices, RF ballast for hgh eficieny lighting etc.
Most of the center-band racket, however, comes from a class of hardware called Industrial, Scientific, and Medical (ISM) equipment operating under Part 18...mainly diathermy and materials testing. Sometimes these signals reach appreciable distances, so it's fortunate that they generally don't extend too far fron the band center.