The idea that the company owes them anything for their unsolicited work is misguided. And, if they present the bugs for money under the implicit threat of selling the information to people who would harm the company, then it's extortion.
2. If said person doesn't present the bug to the company, but just goes straight to selling it to the highest bidder it's not extortion. If the company does not provide the right incentives (via e.g. bug bounties), isn't it their own fault if they get pwnd? They clearly don't value security.
Not to mention them getting "pwnd" creates a lot of collateral damage in the form of innocent customers.
Do you think it's reasonable to say the the ethics of what you call "extortion" should depend with how big the company is? I'm obviously not advocating for making a small company pay more than they can manage
That framing is strange to me. If they want to offer a bug bounty, then they can. But, it's their choice. Maybe they'd instead rather engage a security firm of their own selection.
But, whatever the case, to say "they should pay the money because they can afford to" isn't right to me. I don't believe the definition of extortion changes based on how big the target is or whether it can afford to pay.
In fact, the line of thinking in some of the comments here is so far off from what seems obviously ethical to me that I've had to re-read a few times to ensure that I'm not missing something.