What you found was inconclusive and weak. You found no examples of blocking, yet the stories are claiming that blocking is going on. Protocol identification hardly justifies being called DPI, and DPI is not illegal or necessarily a bad thing.

Are anti-spam, anti-virus, and Intrusion Detection Systems also illegal in your country? We have people in this country that claim these things are illegal too arguing that it breaks wire tap rules and that you need two-sided consent. But would a spammer and malware pusher ever give you permission to inspect their traffic?

The DPI found in caching is different from the one found in differing, where it limited any traffic based on protocols.