Imagine placing your bike in a bicycle parking rack and using your own cable lock to protect it from being stolen.

What if someone came and added another cable lock that you don't own the key to or you don't have the password combination for? If you were to forcefully remove it yourself, you could be mistaken for a thief and, if you threw away the proof that you own the bike, I can't figure out a way out of this, unless there are surveillance cameras around.

Same story with a yard door or gate (like this one). If someone added another lock, you could have a hard time getting in/out your own property.

Are there any laws against such "pranks"?

Asking for two reasons:

  1. Out of curiosity
  2. In case I'm ever in such a situation, I'd like to know how respond in a legaly acceptable manner

First off, I wouldn't assume that this is always a prank. This is a rather infamous tactic used by bike thieves. These thieves add a second lock to "discourage" the owner from taking their bicycle, wait a few days, and then remove both locks, thus stealing your bike. Don't wait, get your bike out right away.

As long as this is your own bike, you don't have much to worry about. It would generally be helpful to call the police, so that they might make a note of it. They might not be able to help you cut the lock, but they will make a note of the incident. It might also be a good idea to register your bike.

Getting into the law part...

If you were to ever be charged with a property-related offence (which I doubt would happen), you probably wouldn't be able to be found guilty. In Canada, the relevant section would be §35 of the Criminal Code.

To summarize that, it basically means that you can't be guilty of an offence if you believe that another person is about to render your bike inoperative (through addition of the second lock), and that your act that constituted the offence would be preventing or stopping that. Don't forget, the bike has to be yours as well.

  • A plain English reading of the Canadian law you've linked to does not support your conclusion. The particular variant of Canada's "defence of property" defence that you're citing requires that another person "is about to damage or destroy the property, or make it inoperative, or is doing so". That plainly isn't the case if the additional bike lock has already been applied; the wording implies that the crippling of the bike would need to either be imminent or in progress, not in the past.
    – Mark Amery
    Mar 6 '16 at 22:48
  • @MarkAmery In that case, (ii) would be in effect: They believe on reasonable grounds that is about to take the property, is doing so, or has just done so. I agree though, it seems worded as to imply that property is an estate of some sort though. However, the fact that a bike lock has been applied qualifies the is doing so part of that section you noted - the additional lock is in the process of making the bike inoperative.
    – Zizouz212
    Mar 6 '16 at 22:52
  • Hmm. I don't think your interpretation of "doing so" is what the statute's authors likely intended. You're assuming that once I've made some of your property inoperative in a reversible way, I'm constantly in the process of making it inoperative until the moment that it is made operative again, and that you are thus free to take "reasonable" acts to make your property operative without fear of law. That's an arguable reading, I guess, but the more ordinary one would be that I am "making" the bike inoperative as I apply the lock, and thereafter I have "made" it inoperative (past tense).
    – Mark Amery
    Mar 6 '16 at 22:56
  • @MarkAmery That's also a fair argument. But, anything that has been rendered inoperative is a constant operation. Even if the initial act of applying the lock rendered it inoperative, the fact that the lock is still there continues that, thus still rendering it inoperative. Nevertheless, I believe that the (ii) case of that subsection would make a strong argument here. The fact that another person has added the lock provides reasonable ground and belief that another person may attempt to steal it. I think I'm going to edit my answer around that now.
    – Zizouz212
    Mar 7 '16 at 1:16

I would suspect it is similar to booting a car which is generally illegal unless it's a cop that did it.


Presumably in the case of the boot you would call the non emergency police line and they would come do "something". But in the case of a bike you would need to prove you own it. I would recommend registering your bike.


I couldn't find anything about property in general being detained by another person.


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