Measures, including methods, apparatus and non-transitory computer-readable storage mediums, are provided for processing browser sessions in a telecommunications network, the telecommunications network comprising a service provider network operated by a service provider responsible for providing telecommunications services to a plurality of subscriber client devices. The measures include, at an entity in the service provider network: receiving, from a subscriber client device in the plurality, a browser session request; transmitting the browser session request to a server entity located outside the service provider network; receiving, from the server entity, a browser session response in relation to the transmitted browser session request; transmitting the browser session response to the subscriber client device; and modifying, prior to the respective transmittal, at least one of the browser session request and the browser session response according to one or more browser session processing modification rules.