Yes because we are able to see much deeper into people's minds - their thoughts, beliefs, emotions much more than face to face when only trivial topics are usually discussed. So we are not used to seeing so many opposing views and this leads to a lot of frustration. We may avoid certain people in real life like hunters, religious people, paleo dieters, etc but on the internet we can't help but be exposed to these beliefs such as on Twitter and YouTube. Our comments and posts are exposed publicly in many cases so anyone can comment. I am often teased about my food choices by people who are on heart medications, even so called friends and family. These opportunities are much less than in the real world where we aren't talking to these people on a daily basis.
While certain aspects of the internet may be maddening, such as ads and broken links, the net as a whole is no more a cause of anger than is a telephone or a screwdriver. Do encyclopedias make one angry? Perhaps misuse of the net is a cause of anger. Perhaps the question is too broad.
Most of the time when I use the internet I feel fine. I know how it works and I can maneuver through it with ease. What makes me angry is when I read an article or something with comments...And I read those comments. There are some people who are natural haters and feel more comfortable spreading hatred behind a computer screen. I think if you ignore those people you will have a much happier time.