Yesterday I checked in at LAX for an international flight (airline not named for obvious reasons).
Upon giving the staff my passport and ticket, there was some ticketing issue that required some time to resolve - a ticket number had been issued.
Fast forward several minutes later and I was asked for my passport again, by the same person.
They were supposed to still be in possession of it.
There was another delay and I found out that a staff member of the airline willingly and knowingly gave my passport to another passenger, who had already left the check-in area. The passenger had to be called over the speaker to return to the check-in area.
Clearly there was great risk, plenty of time and opportunity for my identity to be stolen and given the recency, that cannot be ruled out. It is reported that identity theft does not occur immediately after details have been stolen.
I eventually got my passport back and the staff member in charge did not apologize, however admitted to an intentional breach of security and safety.

Has this happened to anyone before? What action can be taken, legal or other? I am yet to hear back from the airline after submitting feedback.
There are costs to replace the passport, plus costs for new visas that I don't know if the airline will cover.
I'm so broken by this; I cannot trust this airline and they did not even offer a simply apology.

Thankyou in advance to anyone that can help.