If you want work in computer security, then you really shouldn't have a record of fraud. If you want to make pizzas, then you're not likely to defraud anyone but your employer; so it's her lookout. A blackmail conviction is a danger to other staff; it's the employer's responsibility to protect their employees against that risk.

This guy seems to be on probation, and under supervision of SOCA - he hasn't yet completed his sentence. Are we talking USA? He's a felon, and in most US states he will never again be allowed to vote in elections.

In this country you don't have to disclose prior convictions to anyone, beyond a certain date - I think something like ten years. I agree with that. In the same way, expired convictions can't be taken into account in sentencing deliberations. I agree with that too - I do think convictions should expire. Past acts shouldn't follow you around forever. But if you're on probation now for two serious crimes, I think it's crazy to say that a prospective employer shouldn't be allowed to ask, and to rely on your answer on pain of instant dismissal.

And FWIW I don't agree with the US practice of denying felons the vote.