Police and fire trucks descended on Cannes' Palais des Festivals convention center as attendees were evacuated to safety on Thursday.
Bomb disposal teams were sent to intercept the suspicious suitcase in vain.
"I'm hoping that maybe this is a turning point," former CIA Director John Brennan said.
Trump supporters chanted "lock her up" hours after it was reported that former presidential candidate Hillary Clinton had been sent a "potential explosive device."
Things didn't turn out as planned for the pranksters at Newark International Airport, New Jersey.
The game against Bournemouth was called off following the discovery of a suspicious device.
A terminal building was evacuated and flights diverted at the UK's sixth busiest airport