Three out of four children have seen Internet images that disturbed them, according to a new poll commissioned by the NSPCC.
377 out of 497 votes cast by children in the poll claimed to have been disturbed by Internet images.
One child posted a comment on the message board of NSPCC children's website There4me.com saying: "I've seen violent images I didn't search for. I was freaked out." Another youngster said his eight-year-old sister typed in 'pictures of animals' and ended up with pornography adverts.
The NSPCC said it wants social networking and video hosting sites to remove all offensive and harmful material within hours of finding it. In February it was revealed that a rape video on popular internet video sharing site YouTube was online long enough for 600 to view it and comment.
Policy adviser Zoe Hilton said: "We are alarmed by how easy it is for children to access disturbing internet material.
"Children are just a few clicks away from innocently stumbling across upsetting or even dangerous pictures and films such as adult sex scenes, violent dog fights, people self harming and children being assaulted.