Should you use Login with Google or Login with FaceBook in other sites?

Many sites are offering the facility to Login with Google or FaceBook (using OAuth or Open Authentication). This is easier for us so that we do not need to create and remember passwords for these sites. 

Just a thought came to my mind that at a later time (not sure if this is the case now) Google or FaceBook will update their privacy policy such that they can use the information to login to the third party sites and index our data! Google is the biggest online advertiser, so they will use this data for sending adverts.

It may be okay to use this facility for kind of news sites, but for sites that have sensitive data, it is advisable to use a username and password combination.

Moreover, when using this facility to gain access to third party sites, we will be shown the list of permissions that we are granting to the third party sites. If we are giving offline-access, the third party site can access your Google/FaceBook account at any time without your intervention and will be able to post in Google+/FaceBook. So carefully understand and give permissions to your account to the third party sites.

Note: A new app by Intel and McAfee named TrueKey is now available which stores your credentials for different sites. The app then auto-fills the information on the login page. Worth trying.