There are some battery draining tricks you can do with Bluetooth apps on a phone to drain the device batteries. Essentially if you did a ton of device queries to every BLE device visible, you could drain the batteries of every device in range. Transmission is probably a heavier battery drain so just making them talk to your phone creates drain. It’s a single device example, but in a bar once I was showing a co-worker…
Another thing that's basically a real security hole/opportunity with BLE sniffing is to record the unique IDs of all the BLE devices you can see, along with geo-location data. Do this enough places and over time, and you get a map of what devices are where and at what time, with the assumption that the devices are probably linked to people. Expand that to a government placing little innocuous BLE sniffers all over th…
Creating a BLE based cop detector would be a neat way to sign up for harassment and surprice traffic stops. Unfortunately it would likely also work for identifying other groups.