On 11/28, around 11pm I spotted at least three ad hoc police checkpoints set up at the following intersections in BJ:

*ChangAn and Dongdaqiao
*GuangHuaLu and Dongdaqiao
*RitanBei Lu and Dongdaqiao

At the second one, I spotted three cops wait for two scooters heading southbound on Dongdaqiao. Once they got close, the three of them ran out into traffic and stopped the two scooters by surrounding them and pulling out the keys. Both were wearing helmets and did not appear (from my distance) to be obvious offenders who ruin it for others. But I do not know what happened prior to what I saw (perhaps they evaded a prior stop).

Anyway, wondering if some renewed enforcement program is underway.