About Someone else's presentation

It was so nice to listen and watch the presentation of whole classmates. And it was very nice to see whole students each faces. Everyone did really great job. One subject was so popular that was social networking. From the John's presentation, Social Networking: Better or Worse than the Real thing?, it was very interested. Every thing in the world has cons and pros.
Advantages of SNS are that social networking sites have made the  world a smaller place. And SNS also give the notion of unlimited availability where you can literally make new friends and stay connected with others as you sleep.
Disadvantages of SNS are that Privacy and we can become less social-able in real life.
Social networks seems to be the "new" thing now. Businesses are now even using them for promotional usage and it's FREE for them. However, we should be careful to use and pay attention.