Talking to people you know nothing about a lot of teens and young children talking and meeting people they don't know
One of the biggest disadvantage of computers is that it keeps 'real' relationships from happening, if the computer is used as a convenience, we have lost the real reason for being human or to connect as people.
A computer is a piece of technology, and while it can connect people with information and each other, it tends to be very impersonal. Computer interaction lacks many of the cues we get when we talk face to face. It can also provide an anonymity that causes people to act in ways that they would not do in public.
Computers store data in highly volatile storage media. If a hard drive crashes, you may lose a lot of valuable data.
The computer is very useful machine but children waste their precious time by playing games on computer.
It wastes time on playing games, and these days all people have a computer. In there house so every one is wasting his\ her time and I am sure of that... ;)
A computer is a very useful thing. I think even the most useful things can be harmful if it's used excessively. In today's world, the computer happens to be children's most favorite toy. This has several disadvantages. While it obviously affects the amount of time they spend with their family and friends, it can also have a bad impact on their studies. These days most children will sit down at the computer the moment they get back from school. Computer games are a rage with kids and they get hooked to them and neglect their studies in the process. That, I guess, is the only disadvantage and it has more to do with us than computers. If we impose limitations on our kids and train them in such a way that they give the due attention to studies and family duties and responsibilities than this won't count as a disadvantage of computers either.
As compared to what? Are you asking what can go wrong with a computer OR what can go wrong while using a computer?
Computers are very engaging and can exercise a strong "holding power" on children as well as students. They seem to mesmerize children. Therefore we should monitor the amount of time a student spends before a computer.
If the software is not age-appropriate, students are likely to become frustrated and associate a
computer with failure. Younger students with access to software which is not age appropriate may be exposed to such negative influences like violence, abusive language, and over stimulation from fast-action graphics. Frequent computer sessions pose physical health risks for them. The most frequently cited risks are visual strain, harmful effects of radiation, posture and skeletal problems.
Most importantly for Surfing the Internet, parental/teacher involvement & control is a must.