It's a net neutrality whodunnit: Boffins devise way to detect who's throttling transit
https://www.theregister.co.uk/2018/08/24/caida_transit_neutrality_measurements/
Back when net neutrality was a thing, engineers at the Center for Applied Internet Data Analysis (CAIDA) tested US interdomain links, and found them mostly flowing freely.
News of Verizon throttling a California fire department's data suggest things have already changed in America, but if CAIDA's work gets legs, the world will at least have a new way to detect that kind of behaviour.