If you guys have no idea as to what exactly is wget.. Install it (It should be installed onto your linux distro by default) and then issue this below command for some basic intro:
Then onwards, this below link should be a great source to learn all specific stuff you may want to do with it... And for Social Network fans.. you will understand how he could download so many pictures with this tool once you are done reading the guide... Check it out...
Tc and have a great weekend,
Ananth S Gouri