According to Gal, "Bad actors will certainly use the information for social engineering, scamming, hacking and marketing."
While the full database was just recently leaked, the information is from a hack in 2019.
"This is old data that was previously reported on in 2019. We found and fixed this issue in August 2019," said Facebook spokesperson Liz Bourgeois.
Previously, the data was being sold via a Telegram bot that let users to query the database for a low fee. Now that it's fully out in the open, it's more likely your data could be used maliciously.