The electrical signals can be replicated, but who bother, so
difficult and get caught = die.
SMRT logs every top-up, transit (MRT, LRT, Bus). So if the top up
minus away transit fare is negative (below $1), haha... they know
you cheat straightaway.
And no! You cannot bluff McDonald's also, because the EZLink
company also got log... muhahhah.