I have social site links of user and i want to access information from these link
https://www.facebook.com/username
http://en.wikipedia.org/wiki/user-name
https://twitter.com/user-name
http://www.youtube.com/user/user-name
http://www.flickr.com/photos/user-name
i want to access information without user logging in
Without login you can fetch the limited information using the username. Since for the rest you have to ask permission from the user and for that you have to implement the facebook login.
You can use the Graph API to get the info-
http://graph.facebook.com/username
To get the profile picture-
http://graph.facebook.com/username/picture
Youtube
You can use the Youtube API
http://gdata.youtube.com/feeds/api/users/<username>/uploads?v=2&alt=json
Similarly you can search for the other APIs..