Of course it can make you crazy, like anything else. You have to close your laptop, put your phone in your purse or pocket, turn the *** mp3 player off, and just spend time face to face with other people, your loved ones, your family, your children, your friends, your pets, your coworkers, just walk down the street or in a park and enjoy the world around you. Sing, draw, paint, knit, go running, hit the gym, make dinner, do something that takes you away from the Net for a little bit. That's 1,000 times better for you than anything you'll find online (sorry, MTO!).
The overwhelming glut of information on the Internet will deprive a civilization of the wisdom to sustain a good life, according to one of my studies.
I believe it also applies to technology in general. Cell phones and video games, for example, are convenient and fun, no doubt; however, when you can't sit for twenty minutes in a doctor's office waiting room or on a twenty-minute commuter bus ride without picking one of them up, that is sad.