In London the Freedom Pass is an Oyster Card and tracks every journey that is touched in / out for. But the joy is that unlike the real Oyster you don't have to touch in / out if you don't have to - that is there is no penalty fare for not touching out at the end of a journey!! TfL makes millions out of over-charging hapless commuters and tourists 'cos when they don't touch out they get slammed for the highest fare for the day based on where they started. On the TfL buses yes you have to touch in, but you don't have to touch out. The biggest issues with 'security' are the damned CTV cameras - each bus has about 16!!