Will you login to a site....

You are right but not completely. If you are joining in that sites from a computer that is not your own then others will be able to do abything with your login. On the other hand if you have your own computer you shouldnt be afraid of anything. Some PTC sites for example allows only one person from a particular computer to join them. And in addtition if you want to other people not to see anything you can just delete cookies and history of your internet browser when you are finishing your session on a computer. Then nobodu will see anything.

They may have a 'hidden' logout link or you have to use a different browser. Normally I use Firefox to surf so-called paying sites. One site which I joined appeared not to have a logout link. On the first incidence I simply exited the browser even though I knew it was risky. On the second time I thought this could not be so I pressed the right mouse button and moved the pointer over the area where we could see the logout link. There it was. By the way I am not active on this site and I could not remember it offhand.

maybe you missed out the logout button? Some sites don't emphasize well enough where is the logout button. It will really be odd if there's no logout button. It took me like a couple of weeks to figure out the logout button of ptcnation. Which sites are you referring to? Maybe me or someone else could be of help. Goodluck!