Zkdli,
And while I remember, the only reason for the Infringer spotter is because the most serious infringer this year was not spotted by the ATCOs until after it had crossed the Heathrow climbout lane very close to a departure.
Whilst working over the Bank Holiday weekend it was comforting to note that whilst the infringer spotter was meant to be doing their stuff I was involved in two fairly significant infringements into the London Zone, neither of which were spotted by the spotter.
Money well spent