Account lockup questions

I hope it's just me panicking but what actual information do you need to send in a KYC account lockup?

If your account gets locked does this mean your money is gone forever. Has anybody ever got their money back.

When do lockups happen, when you try to withdraw?

I want to use binance but these lockup stories are petrifying.

I'm an ex forex trader and brokers used to target profitable traders with artificial slippage. However, they couldn't ever use KYC to steal our money.