Depends what it is.
Let's say you accidentally post a link to a supposedly private web page you wrote, on which you've posted your bank account info and password. Someone finds it, logs into your account, and takes all your money. They've still stolen it - just because you made the theft possible doesn't make it legal to steal it. It's just like accidentally leaving your car unlocked with your laptop on the back seat. It's still theft if someone takes it.
Richard