Two ISPs, Cox and Comcast, have stated that they engage in this practice, where they limit users' bandwidth by up to 99%. Today most if not all Internet Service Providers throttle their users' bandwidth, with or without the user ever even realizing it.

Do all ISPs throttle bandwidth?

Typically, ISPs only throttle what they consider to be a “heavy” internet user — as per their own definition — during “times of high traffic.” A typical internet user will likely never experience network throttling. If your internet is slow, there may be another reason behind it.

How do you tell if my ISP is throttling me?