The Daily Mail and the BBC report on another Rapidscan back scatter X-Ray machine "trial" deployment at a British airport.

Why is Manchester Airport inflicting another "see through your children's clothes" scanner on the public ?

As noted by Dr.David Murakami-Wood, on his notes from the ubiquitous surveillance society blog:

You would think after 4 years of trials at Heathrow, that British airports would now be able to work out whether or not they could and more importantly, should, use the various varieties of body scanners that are now available

What has changed since 2004 ? See the articles by John Lettice of the The Register articles from that time.

There is still no "safe dose" for even low levels of ionizing radiation, in this case X-Rays

The fact that the operator of the machine will (aping the trials in the USA) sit in a room away from the actual machine, and be hidden from the members of the public who are being processed, may reduce the number of lawsuits for cancer etc. from machine operators and security guards, who will inevitably get a larger cumulative dose of X rays through day to day proximity to the machine.

Hiding the operator from view is a two edged sword - it may reduce the number of complaints about abusive or lewd comments made by the operators to the passengers, or between security staff, (as noted by Dr. Murakami Wood) but it will also make it impossible to tell if you are being snooped on by a man or a woman, something which will embarrass or offend many, many people, not just various religious sects.

The law on Child Pornography has actually changed since 2004.

It was, even back in 2004, it was a criminal offence to create or copy (even for a fraction of second) an indecent Image or Pseudo-image of a Child. Since 2004, the definition of a Child for this purpose has changed - it now includes anybody under 18 years of age (previously 16 years).

See the wikipedia article on the draconian, inflexible and often bureaucratically misinterpreted Protection of Children Act 1978

There is no legal dispensation for "see through your clothes" imaging scanners or their operators or the companies or government organisations or law enforcement officials, who inflict them on the public.

As the picture from the Daily Mail show article shows,
It does not matter if the Manchester Airport's Head of Customer Experience Sarah Barrett thinks that the images are not illegal, her personal opinion has no legal standing.

Ms Barrett said the black-and-white image would only be seen by one officer in a remote location before it was deleted.

"The images are not erotic or pornographic and they cannot be stored or captured in any way," she said.

It is completely false to claim that the images "cannot be stored or captured in any way".

The Daily Mail article is actually illustrated with digital camera screen grabs from the display monitor !

The system uses a computer, therefore images are processed and stored. Who has maintenance access to these systems ? How, if at all, are the temporary image processing results actually securely erased ?

Putting an operator in an private room to view the screen, means that they can use their mobile phone cameras to snap "unclothed" images of celebrities etc. - or will there be a CCTV camera watching the "see through your children's clothes" scanner operator as well ?

Just as in 2004, there is still no justification for imaging rather than any other sort of metal or explosives or illegal drugs detection used on live people.