A sublime confidence in one's pupils is needed before letting them fly solo, and the a stimulation of intellectual joy is vital in appreciating the profundity of the experience of cross-world interaction. We find it very hard to condone the blocking, through financial or ideological constraints, of this form of education from those who would clearly profit. The school community has, again, to find its own equilibrium and to make choices for itself. There is no safely walled-off adventure playground in life, and to believe such an idea is practical on the Internet is to ignore both the technical and social realities of the system, as well as to deny the serendipities only accessible beyond the playground's gates. So it behoves all in responsibility to seek and weigh the arguments.
Complete delay is too easy a decision, although in some cases is possibly the correct one.
The scenario for accidents to pupils is serious - but letting them by default experiment alone and unsupervised at home or in a commercial cybercafe environment breeds other problems which might be averted by an early installation at school. We hear of one independent school with eight terminals. That luckless person had doubtless been so taunted by colleagues about the devil's new medium that he wanted to lurk behind a safety screen while others tested the water. Your teachers and pupils will thank you for well beyond their working lives. This is an area where the professional advisor is driven by so many conflicting forces that no blanket solution can be offered to a school.