A computer-implemented method can include receiving, in a system that maintains web notebooks for a plurality of user accounts, a request for a web document from a client computing device; determining whether a portion of the requested web document is included in a web notebook associated with one of the plurality of user accounts; and when it is determined that the portion is included in a web notebook associated with one of the plurality of user accounts, providing for display by the client computing device a highlighted version of the web document having a visual indicator that highlights the portion. Determining whether a portion of the requested web document is included in a web notebook associated with one of the plurality of user accounts can include determining whether the portion is included in at least a threshold number of web notebooks associated with distinct user accounts.