In a development that net neutrality advocates believe could herald the start of an unwelcome trend, AT&T said on Monday that it would introduce usage caps for its fixed line broadband services that would go into effect on May 2. AT&T, which scrapped unlimited data plans for its wireless customers late last year, defended the move as an integral part of the company’s mission of delivering “a great experience for all our Internet customers” and further observed that the new policy will affect only 2% of subscribers that consume “a disproportionate amount of bandwidth.” Although Comcast, the nation’s largest cable operator, has capped fixed line broadband usage since 2008, analysts predict that Charter Communications, Cox Communications and other cable or wireline ISPs will soon follow AT&T’s lead. Under the new policy, AT&T DSL subscribers will be limited to 150 GB of data usage per month, and subscribers to AT&T’s fiber-optic U-Verse broadband service will be limited to 250 GB per month. Customers exceeding these limits will be assessed a $10 fee for every extra 50 GB of data they consume each month although users will not be charged until they have exceeded the cap three times. An AT&T spokesman also said customers will be notified as they reach usage thresholds that equal 65%, 90% and 100% of their monthly caps. Asserting, however, that data consumption is rising rapidly among all web users with the emergence of video streaming, online gaming, and cloud computing services, net neutrality advocates predicted that larger numbers of customers than those cited by AT&T are likely to incur overages. Charging that overage fees “[bear] no discernable relation to underlying costs which are estimated to be mere pennies per gigabyte,” Free Press research director S. Derek Turner called on lawmakers “to investigate Internet overcharging schemes to ensure that they are not unreasonable or anticompetitive actions.”