A method of controlling webpage behaviour on a web enabled device comprising the steps of: receiving a webpage at the web enabled device, wherein the webpage comprises a tag for calling a client side module running on the web enabled device when the webpage is delivered to the web enabled device; monitoring a user interaction with the webpage, using the client side module; determining whether predetermined conditions are satisfied, and where the predetermined conditions are satisfied, carrying out the further steps of: capturing details concerning an intended result of said user interaction, using the client side module, the intended result being an intended resulting operation of the web enabled device; cancelling occurrence of the intended result of said user interaction using the client side module; carrying out additional processing using the client side module; determining a controlled result, using the client side module, in dependence on said intended result and the additional processing; and causing the controlled result to occur, wherein, the predetermined conditions comprise the user interaction being one having an intended result of causing a page transition at the web enabled device, which would lead to navigation to a target page and the controlled result is a controlled resulting operation of the web enabled device and comprises one of: i) no action in response to the user interaction, such that navigation is cancelled; ii) a regeneration of the intended result, leading to navigation to the target page but after some delay introduced by the additional processing; and iii) a modified result which is a modified resulting operation of the web enabled device, leading to navigation to the target page but with a modified uniform resource locator query string or with referrer information deleted or leading to navigation to a different page. receiving a webpage at the web enabled device, wherein the webpage comprises a tag for calling a client side module running on the web enabled device when the webpage is delivered to the web enabled device; monitoring a user interaction with the webpage, using the client side module; determining whether predetermined conditions are satisfied, and where the predetermined conditions are satisfied, carrying out the further steps of: capturing details concerning an intended result of said user interaction, using the client side module, the intended result being an intended resulting operation of the web enabled device; cancelling occurrence of the intended result of said user interaction using the client side module; carrying out additional processing using the client side module; determining a controlled result, using the client side module, in dependence on said intended result and the additional processing; and causing the controlled result to occur, wherein, the predetermined conditions comprise the user interaction being one having an intended result of causing a page transition at the web enabled device, which would lead to navigation to a target page and the controlled result is a controlled resulting operation of the web enabled device and comprises one of: i) no action in response to the user interaction, such that navigation is cancelled; ii) a regeneration of the intended result, leading to navigation to the target page but after some delay introduced by the additional processing; and iii) a modified result which is a modified resulting operation of the web enabled device, leading to navigation to the target page but with a modified uniform resource locator query string or with referrer information deleted or leading to navigation to a different page. capturing details concerning an intended result of said user interaction, using the client side module, the intended result being an intended resulting operation of the web enabled device; cancelling occurrence of the intended result of said user interaction using the client side module; carrying out additional processing using the client side module; determining a controlled result, using the client side module, in dependence on said intended result and the additional processing; and causing the controlled result to occur, wherein, the predetermined conditions comprise the user interaction being one having an intended result of causing a page transition at the web enabled device, which would lead to navigation to a target page and the controlled result is a controlled resulting operation of the web enabled device and comprises one of: i) no action in response to the user interaction, such that navigation is cancelled; ii) a regeneration of the intended result, leading to navigation to the target page but after some delay introduced by the additional processing; and iii) a modified result which is a modified resulting operation of the web enabled device, leading to navigation to the target page but with a modified uniform resource locator query string or with referrer information deleted or leading to navigation to a different page. i) no action in response to the user interaction, such that navigation is cancelled; ii) a regeneration of the intended result, leading to navigation to the target page but after some delay introduced by the additional processing; and iii) a modified result which is a modified resulting operation of the web enabled device, leading to navigation to the target page but with a modified uniform resource locator query string or with referrer information deleted or leading to navigation to a different page.