If you want "mass surveillance" with thousands of suspects, millions of requests per subject (the paper mentions 20 requests per second IIRC), over weeks ... you probably get blocked and/or caught.

Also, your suspects will be "significantly unhappy" if your espionage costs them 11-18% of their battery per hour. Even without other usage, the battery would be dead by noon.

And lastly, this attack uses so much bandwidth that video streaming is impacted. I would guess that it probably needs about 1 MBit, which is 11 GB per 24 hours.