Senator Ludlam asked:
a) Has there been any kind of quantitative or qualitative research on the likelihood of accidental or inadvertent exposure to refused classification material online?
b) Is there any evidence pointing to the frequency with which that occurs?

Answer:

a) Due to the size and dynamic nature of the internet it is not possible to quantify the probability of being exposed to Refused Classification content on the internet. Mandatory ISP-level filtering of the Refused Classification Content list will, however, help prevent inadvertent exposure to URLs on the list.

b) The Australian Communications and Media Authority (ACMA) currently receive approximately 1300 complaints per annum in relation to overseas hosted RC content.
The number of complaints received by the ACMA in 2008-09 (1075) was more than double the amount of complaints received in relation to such material in 2007-08 (521).
As part of its independent testing of filtering technology, an ISP (which claims to have 1 per cent of Australia's internet subscribers), found that in a five day period, there were
20,000 ‘hits' on a list of 198 URLs that contained child sexual abuse images.