Search information, work, you can take photos, download apps, meet new people, to be up to date, if you have a problem or if you are in a dangerous situation you can warn parents or friends with the mobilel, we can talk with people that we haven't got in our day a day because they are working or living in another country.
AGAINST:
It can cause withdrawal, disconnection with reality and loneliness, High degree of dependence, discourages physical activity and outdoor play may cause disinterest in other forms of entertainment, you can spread obscene, harmful or aggressive people comments, Health problems such as those mentioned at the beginning ( more in children), people that you don't meet can see your photos and it can be dangerous.
What do you mean about to have a mobile phone in our hands? Do you think that is it a good way for to be comunicated with the civilization or that we should to be carefull with it?
On the one had, with mobile phones we can search information if we have internet.