Your passwords are safe as long as you have done your part, i.e. followed best practice on how to set up your passphrase for accessing your information. LastPass implemented a system that is durable, as long as your HW is not compromised or you are somehow duped into giving away your password you should expect your passwords to be safe. If you are worried, change your passphrase in accordance with best practice and you should be fine. Breaches will happen, their architecture saves your data - but that means we have to do our part and follow recommended process/practice.