https://thenextweb.com/insider/2018/06/15/comcast-just-ditched-its-throttling-system-but-dont-celebrate-just-yet/

Comcast is reversing course on a throttling system first deployed in 2008 as a means to deter heavy internet users from exceeding their monthly data allotment.

As reflected in a June 11, 2018 update to our Xfinity Internet Broadband Disclosures, the congestion management system that was initially deployed in 2008 has been deactivated. As our network technologies and usage of the network continue to evolve, we reserve the right to implement a new congestion-management system if necessary in the performance of reasonable network management and in order to maintain a good broadband Internet access service experience for our customers and will provide updates here as well as other locations if a new system is implemented.