Yesterday, I logged in to Google from a rather public computer using Google Chrome to check my emails. As soon as I logged in, a popup window appeared and informed that my bookmarks, passwords, history have been synced using Google Sync. It did not ask for any confirmation or permission from me, everything was automatically synced.All I could do was to press Okay to have been informed.But that is not what I wanted. I simply wanted to check my email, log out and leave the machine. After the incident, I had to painstakingly remove everything from the machine. Logging out from Google Sync did not help.Could you please tell me how do I stop Google Sync from syncing in the untrusted machines and at the same time keep it active in the trusted machines?As one colleague suggested, it was safer to use Firefox rather than Google Chrome under the scenario described. But what if Google Chrome I decide to keep using Google Chrome? 
How not to use Google Sync at a particular computer?
gmail;google;security
As I know, logging into Google does not give sync permission to the browser unless you sign in to Google Chrome which you may be prompted for, when opening Google Chrome browser. So pay attention if you are prompted for such a thing.Also on a public machine, I recommend using Incognito mode for Chrome (by pressing CTRL+Shift+n) and Private Browsing mode for Firefox (by pressing CTRL+Shift+p) and this will prevent your personal data from being synced and also the browser will not store your session history, cookies or anything else after you close the window.Other browsers like Opera, Internet Explorer etc. have similar modes to protect your privacy and you can find these modes in menus.