title: Facebook App Login: How to control expiration date of an image URL I got?
body: <p>I'm developing an app, which uses the facebook login. After login the user must set additional informations and a profile picture, with the picture being provided from that logged in facebook account as well. Now the whole account details, including the URL to that profile picture, are saved in my database.</p>
  
  <p>To my surprise the profile picture has suddenly stopped working. Opening it's URL in a browser gives me this message "URL signature expired"</p>
  
  <p><a href="https://scontent.xx.fbcdn.net/hphotos-xpa1/v/t1.0-9/p720x720/10846350_10204966809307370_2779189783437306470_n.jpg?oh=245bbada6c23f280a1e531e724be85ed&amp;oe=56894D69" rel="noreferrer">https://scontent.xx.fbcdn.net/hphotos-xpa1/v/t1.0-9/p720x720/10846350_10204966809307370_2779189783437306470_n.jpg?oh=245bbada6c23f280a1e531e724be85ed&amp;oe=56894D69</a></p>
  
  <p>Downloading those photos and save them to my own server is not really an option for me. Is there anything I can do to make that URL durable?</p>