Bonding yourself via GND pin of an USB-port?
You should NOT connect your anti-static gears to USB ground pin. The USB ground is SIGNAL GROUND. An ESD event can surge along the signal ground and elevate its potential relative to other ICs inputs (called sometimes as "ground bounce"), and it can damage internal ICs. If you don't have Earth ground on your workspace, at most you should use SHIELD of the USB connector, but not GND. The SHIELD usually is properly designed to re-direct and absorb the surge without exposing internal low-votage CMOS ICs to dangerous voltages.