Yes, it can, but it's not the same as giving your password away. 1. you can revoke access throught the Twitter settings. 2. if you use the same password for,

Yes, it can, but it's not the same as giving your password away. 1. you can revoke access throught the Twitter settings. 2. if you use the same password for, say, you're Google account, using OAuth stops this password being revealed to the developer, so they can't access, say, your Google Payments account There's a big difference between giving the site unrestricted access to your Twitter account and giving it unrestricted access to all your accounts (if they use the same password). Let's not pretend there isn't a difference here. Anyway, the site is reasonably descriptive about the functions it offers before sending you through the OAuth process.