What pilot can control a crowd of 1000 or more people? And how?
You would need a lot of marshals and observers. Everybody under your control has to be aware of the risks and the safety procedures.
To get permission to fly over a crowd, the craft must be extra redundant and safe as possible, but at least N+ at least 1 (preferably 2) for engines, batteries, FC's. Extra GPS is also preferable (but only for the emergency RTH).
This does sound like a Matrice600 to me

(A company in the Netherlands sells a craft for >50.000 EURO that is supposed to be certified to fly over crowds and congested areas. Unfortunately some crashed because it only has 1 battery. They have some insurance claims that might end their business)
Only pro operators with such crafts, and a complete ground team to control all variables, and after submitting a full risk mitigation plan and proof of proper insurance, could obtain permission. Still, no one would be able to claim to have >1000 people under control. Not even a police force.