Not totally true Sextus.
There are many public areas where you cannot take a photo of a person without their written permission, such as a beach, park or a school. Often this has nought to do with "privacy" and more to do with you being a "nuisance". You may not be arrested, but your equipment may be confiscated and you will be moved on.
The situation that Wayne refers to with his friend who is a professional journalist is that he would be in breech of copyright as he would be making money from his images/video. The average tourist taking photos/videos of the environment (note, not people) for private use in a public place will be fine. This does not apply to all public areas BTW.
In any case, none of this has anything to do with the situation in this thread. Beyond any doubt, recording someone in a sexual situation without their permission in a place where they have a reasonable expectation of privacy (which includes a brothel, hotel room, private residence etc) is illegal.
These are all outlined in the following articles:
http://www.artslaw.com.au/info-sheet...aphers-rights/
http://www.artslaw.com.au/info-sheet...public-places/
and
http://www.lawstuff.org.au/wa_law/topics/article10