[joemi]

Sure, that's one way to look at it. But also, since you have to actually interact with the server in order to discover such vulnerabilities in it, it could also be viewed as similar to walking in through an unlocked door and looking around. That, at least, is trespassing, I believe.

[tertius]

Or making an inventory list of everything inside. "Oh, here's a filing cabinet, I'll just pull the inventory. Just peeking in..."

[slackingoff2017]

When you connect with ftp or HTTP you get a top level directory or a home page. Same thing as looking through an open door.

[theossuary]

Alright if we want to get specific it's like being blind and touching a home's open front door. Incredulous​ that the door is open you feel around inside for a second and feel a set of keys on the hook. You leave at this point and a week later are arrested for B&E because your fingerprints are on the keys (or you were stupid enough to tell the owner their door was open)