Northeastern University assistant computer science prof Dave Choffnes built an app called Wehe that monitors network usage and throttling; it has users in 161 countries and has been used to produce one of the most comprehensive looks at video throttling by wireless carriers.
Choffnes's research found that while video throttling was ubiquitous (with Verizon as far-and-away the very worst offender), it was not correlated with network congestion. The carriers were just throttling to be dicks, in other words (I'm sure that throttling also sells higher-cost plans to frustrated customers).
The Net Neutrality rules that Ajit Pai just killed allowed for throttling for "reasonable network management," but even under those notoriously loose guidelines, this was probably illegal. It's moot now, since Pai — a former Verizon executive — has eliminated any restrictions on carriers' sleaziest practices.
Choffnes is at pains to point out that Wehe only detects the bluntest, easiest-to-spot forms of network discrimination; practices like paid prioritization and paid peering are invisible except through things like corporate auditing or subpoenas.
And because of differences in their users' mobile data plans, internet service providers such as T-Mobile might throttle one user's internet traffic but not the other's, said Choffnes.
The team also observed that this behavior doesn't seem to have a clear rationale.
"There's no evidence that any of these policies are only happening during network overload," said Choffnes. "They're throttling video traffic even when the network doesn't need to. It happens 24/7, and in every region where we have tests."
New research shows that, post net neutrality, internet providers are slowing down your streaming [Aria Bracci/Northeastern University]
Wireless Carriers Throttle Video for No Good Reason, Researchers Find [Karl Bode/Motherboard]