Alternately, how well does the system handle multiple, repeated scans?  I can imagine (no, I’ve experienced it) being so jammed on a tram that my card could easily be scanned repeatedly as I’m pressed against the reader.  Alternately, in the same situation, others would not be able to scan off at all.  According to the Myki website such situations will be charged as a “default fare.”  Which presumably will be the maximum possible fare from wherever those passengers boarded.  I’m not too sure I would want to be the complaints officer handling all those calls.  Alternately, people may not notice that they’re being regularly overcharged – perhaps that’s how the system will pay for itself!

Some time ago, Roger Clarke, Australia's leading privacy proponent commented “I don't want to be unduly negative, because this is a 10-year-old solution that's been cocked up many times in many places, especially (but not only) in Australia.  But the lack of hard information on the site makes you fear that they may have cocked it up again ...”  Nothing I’ve seen would suggest any of us disagree.