Not entirely accurate. You can borrow against the stock you own, but it's still a loan and the stock is still collateral. Also, the line of credit still has to be approved by a bank who is lending the money and holding the stock as collateral.
And if the stocks go down in value, depending on the type of loan, whether it's on margin or a line of credit, if the stocks go down in value you could face a margin call or the bank can demand immediate repayment of the debt.
Borrowing against company stock is quite risky and is only advisable in a narrow range of circumstances.
Margin accounts are fairly common but you can only borrow so much and if the value of the stocks borrowed against, you can face a margin call, which can create a host of problems for the account holder. So it's fairly risky.