Steven Milloy takes what could be regarded as a Numberwatch-type view of the story, but he then receives quite a bit of flak from his readers. It's almost as though his readers want there to be a cancer cluster because it suits their political agenda that TSA is taught a lesson. Milloy may have been campaigning against junkscience for 15 years, but it doesn't look like his readers are necessarily fully committed to the cause.
I did a Google search and there is a John Hopkins University report which gives the relevant doses in this document (a 13.6 MB download):
It looks like the radiation dose for people going through the body scanner is negligible, and it is still classified as negligible for up to about 650 screenings per year. The dose to 'workers' in the vicinity of the machines, which would I think correspond to the people claiming to be suffering from cancer clusters, is within 100 mrem/year provided there are less than 238 screenings per hour (which is about 4 per minute). To put the 100 mrem per year limit in perspective, it is about a third of the average USA annual background radiation dose.
I seem to recall they found a cancer cluster among workers at Sellafield (Sea scale or whatever in those days).
The trouble was, this was during the building phase. Still, given the way AGW people lay claim to everything I suppose we could allow for a new science of anticipatory issues. Maybe a psychosomatic causality?
I suppose it could just be a cluster? NaH, clusters mess up a nice theory/fantasy.