I was on an LHR-IAD flight earlier this week that was 2 or 3 in line for takeoff and had to taxi back to the gate so they could remove something from the hold.

I was on an LHR-IAD flight earlier this week that was 2 or 3 in line for takeoff and had to taxi back to the gate so they could remove something from the hold. From the conversations I overheard it was a phone that had to be removed from someone's checked baggage.