> freezing all the states of page A If page A requires running substantial javascript components, freezing the state could be pretty hard. What if going back t

> freezing all the states of page A If page A requires running substantial javascript components, freezing the state could be pretty hard. What if going back to the page entails restarting the execution of some javascript to render page elements? Don't dismiss potential security risks as "trivial" either. Maybe it's not a big deal to the person visiting the site, but it could expose the sites to costly hacks.