Teenage bloggers are putting themselves at risk of cyber-stalking and cyber-bullying because they often reveal their names, ages and offline locations, according to new research.

The warning was made in a study of 68 randomly selected blogs produced by individuals aged 13 to 17.

The research was conducted by David Huffaker, a Northwestern University researcher working on a technology and social behaviour programme, and Northwestern professor Justine Cassell.

Huffaker said that half of all teenaged bloggers link to other bloggers, often including a 'friends list', and almost 70 per cent provide a comment section in order to obtain feedback from readers.

The researcher noted that blogs play a positive role from a developmental perspective by offering teens a place to construct narratives and share stories.

"These activities are important to identity exploration, which is one of the principal tasks of adolescence," he said.

"The mechanics of these online diaries, with their opportunities to link to and get feedback from peers, also aids teenagers in creating and maintaining social ties."

The randomly selected teen blogs, equally divided between males and females with a mean age of 15.47 years, were examined for content and the amount of personal or private information revealed.

Seventy per cent of the teens disclosed at least their first name, while 67 per cent revealed their age, and 61 per cent provided their contact information either in the form of email (44 per cent), instant messaging name (44 per cent) or a link to a personal home page (30 per cent).

Nearly 60 per cent of those who provided contact information disclosed the city or state in which they reside.