> threatened me when I tried to collect

That part is not really clear. My understanding is that if he physically threatened you, you could file for a criminal case and he'll be in much deeper trouble than just not paying.

I’m hoping the contract’s execution was contingent on payment being received by you.

It always is, at least in the US. See (the legal doctrine of) https://en.wikipedia.org/wiki/Consideration.

Specifically this part:

> Consideration cannot be illusory

A contract without consideration is void. If you promise to give someone X (that you own) if they give you Y (that they own), and you never give them X, then you don't own their Y, even if it's already in your possession.

You just (non-forcefully) stole their Y—same as if you e.g. asked to borrow someone's phone and then walked away with it.

If only there was a currency that allowed that..

Good luck trying to code a few hundred years of common law into a smart contract.

Start with one step. Then take another. Step by step. Be not daunted.

Did you take him to court over the issue?

Around 2012 was a very problematic time to take someone to court with respect to Bitcoin. This was right around the time the SEC and other agencies were beginning to treat cryptocurrency as a money / brokerage and wanting people to get licenses, whereas almost every operating Bitcoin company had no such licenses.

That sucks

I'm curious. What sort of "company" is acquired for 5 figures? I assume that's in USD and not BTC.

Just a website where I sold people Bitcoins over the Internet in my spare time. I don't think the scare quotes are warranted, I had over $1 million in total volume and it was consistently profitable.