If I am going to grade the lectures about Internet/SNS, I will give Prof. Comer's lecture 5 out of 5 points, and Dr. Yadav's lecture 3.5 out of 5.

The reason is, Prof. Comer's lecture provided a very clear structure about how Internet was developed, why it had a hard time in the early years, how it is different from the traditional telephone network. Also he gave us a clear image of “Internet is a network of networks”, and stated the challenges we're facing.

And since Dr. Yadav, the lectures became more about ethic problems. I saw a lot of ethic / moral problems, and they don't look like have been or being solved so much. For example, SNS is highly developed, people are more likely to communicate online, and spend less time in talking face-to-face – how is that; can that be a problem? My answer