Where do stock market APIs get their data?

It confuses me how stock market API companies can charge so much for access to the stock market data.

How? it is trivial - you set up a paywall, you charge.

So I am wondering where the companies like the two above get their data?

From another provider or the exchange. Exchanges sell real time data access, you know - not cheap and often pay by client. Delayed the pay by client is zero. You can research the details on every exchange website - some times hidden (it is not really something the public needs).

Can I get data from their data source?

Ask an exchange. Be prepared to pay a LOT - they generally do not want to deal with a random guy asking question on internet forums, but talk to companies that do the reselling or offer data for their clients (brokers etc.) and their fees often are quite high (for a guy asking on internet forums). Like tens of thousands USD per month for the agreement.

Can I get data from their data source?

The simple answer is NO.

It would be like saying "United and Qantas buy airline routes from governments, can I buy one?" Answer, no.

(If you think this is "unfair" or "data should be free" or such, unfortunately it's just a case of "whatever".)

"Have corporations made it so individuals do not have the right to access this data ourselves?"

I mean, lots of people believe government should not exist, gold should be the only money, government should control all industry, Euros should be the only money, all Disney movies should be freely available, Disney copyright should last 750 years - "whatever". You're talking major social-political paradigms. Nobody on this list cares, this list is for questions like "how do I use my chequebook" - ask on politics or history if you want to discuss it and/or rant about some particular position on the issue.