Prepaid wireless carrier Boost Mobile says it will start slowing down data speeds for customers consuming more than 2.5 gigabytes a month, beginning in January. In a practice known as \"throttling\" that is common among providers, data speeds for users exceeding the data threshold will drop down to 256 kilobytes per second until the next billing cycle, when data will resume at full speed, Boost Mobile said. On its Facebook page the company explained customers would receive a text notification when they\'ve reached 85 percent of the monthly allotment, AllThingsD reported Thursday. Boot Mobile said it expected the policy to affect only a small number of customers, noting 2.5 gigabytes is equivalent to about 90,000 emails, 91 hours of streaming music, 20 hours of video clips or 400,000 Web page views. Boost Mobile began texting customers in early December announcing that throttling would begin soon, and now says it intended to begin the practice around Jan. 20.