Were their locks even attached to anything?

from here and here (image source)

Maybe the different outcomes are enough to teach the ex-bike-owners some principles about how to better secure their bikes. Like making sure the lock actually goes through every part of the bike.

Good neighbours are great security

found on 9gag

You may not agree but it's hard to argue with results. This bike would have been stolen if not for the actions of that neighbour.

David Bombal : Flipper Zero Hacking

Watch on YouTube

A quick, practical demonstration of Hypponen's Law. If it's smart, it's vulnerable. Without knowing anything about the Flipper Zero device, I'm guessing it's being used to perform a replay attack on the bike lock. If I'm right, it recorded the unlock signal sent from the legitimate remote control for the lock and then transmitted the same signal it recorded at the press of a button.

But not about riding it

from here and here (image source)

I don't see any opening except at the top, so I have to assume this bike isn't going anywhere with thieves OR it owner.

High Security

from here and here (image source)

It'll take a bigger man than me to attempt such a daring robbery. At least during the daylight hours when climbing up that thing makes you into a spectacle. Maybe it'll be better under the cover of darkness.

Or maybe bike thieves will just always prefer the lower hanging fruit (the bikes already on the ground).

Get to know the signs

from here (image source)

If you've never tried to lift one of those signs before you should give it a try. You might be surprised, and you'll probably never use them like this ever again.

Pedal protection

from here (image source)

If there WAS supposed to be a bike attached to that then you clearly locked the wrong part.

What could possibly go wrong

from here and here (image source)

I think this is what they call foreshadowing. Look down and despair at your future, cyclist. 

Put out a BOLO for a barefoot bandit

from here (image source)

Sometimes I wonder if bike locks work on anything.

Nature's Theft Prevention

from here and here (image source)

Of course there's also a bike lock in there (at least it looks like one, though it's hard to tell with all that webbing in the way) so this bike is double protected.

Close but no cigar

from here (image source)

If the first lock doesn't stop the theft, the second and third aren't going to do it either. They're just the same preventative measure repeated multiple time. Best case scenario is if you put a ridiculous number of locks on it then maybe the thief will just consider it too annoying to steal.

If you're going to use multiple preventative measures it would be better to make them different so that if one fails maybe another won't.

At least it won't wander off on it's own

from here (image source)

This kind of thing may work for horses, but it doesn't really make sense for bicycles.

Why not both?

from here and here (image source)

If you want to lose a megabike of information, this seems like the way to do it.

When you forget about the bad guys

found on Funny Junk

Sometimes we use security controls more out of habit than anything else. We forget why they're there and why we need them and so we sort of go through the motions and don't get any benefits as a result.

Here's one way your bike can bee secure

from here and here (image source)

Just in case the bee infestation isn't enough to deter would-be thieves, there's a perfectly good non-infested bike right beside it that would probably be less of a hassle to steal. 

Why not both?

from here and here (image source)

Not that anyone is going to ride away on that or anything, but bike security measures are notoriously bad, and that is just about the most public toilet I've ever seen.

I spy out of the corner of my eye...

from here (image source)

Pretty sure that lock could just fall off if you turned the handle bars the right way. 

At least it won't roll away on it's own

from here (image source)

It almost seems as though this person was only thinking in 2 dimensions and never even considered a 3rd. Not only are they not thinking outside the box, they aren't even thinking outside a square. 

You're not going to get very far in your defenses if you can't see all dimensions of the threat landscape.

It's definitely not going anywhere

from here and here (image source)

Sometimes you have to think outside the box. Instead of trying to prevent something, figure out an alternative where the thing you were trying to prevent is simply not possible to do in the first place.

Of course it's also a good idea to keep alternative threat models in mind too. No one will be riding off with this, but they could certainly carry it away, and that lock looks like you could just slip it over the top of the seat.

At least no one will mess with the lock

from here (image source)

You really have to wonder what the person who did this thought they were accomplishing. The only thing it seems to actually prevent is the bike falling over, and even for that I'm not so sure.