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The esquivalience of mountweazels protecting copyright

The worst thing that can happen to the creator of a copyright work is finding that, after having put significant effort and intellectual skill into their creation, it has been copied by someone else.

For works which comprise a compilation of facts or pre-existing works, or which are likely to be similar by their very nature, the difficulty is showing that the similarity does indeed arise from copying. However, the inclusion of a ‘mountweazel’ or copyright trap can be a simple solution to catch out copyright infringers.

Protecting copyright

Copyright protection essentially protects against infringers copying the substantial part of an original work. The greater the similarities between the works, the greater the inference that the latter work has been copied from the former. However, an identical work created entirely independently will not infringe copyright as it has not been copied from the original. Assuming that the original work has not been kept in a locked room, there will be the possibility that a highly similar work has resulted from copying. Nonetheless the burden of proof lies with the copyright owner to show that the supposed infringer had opportunity to copy the original work.

In some cases the similarities in almost identical works will have an innocent origin and this is particularly true where the underlying content is commonplace or universally accessible. Good examples of this are dictionaries or maps; anyone producing such a work is likely to arrive at a similar output, nonetheless this output will be the result of their intellectual creativity and skill, and this still deserves protection from others seeking to copy their work rather than use their own intellectual endeavours.

The existence of mountweazels

In order to protect copyright some have come up with the ingenious solution of inserting falsities or copyright traps into their work, otherwise known as ‘mountweazels’. Mountweazels are fictitious entries which, when apparent in a derivative work, will go some way to prove copying, particularly if multiple mountweazels are in evidence as the likelihood of their independent inclusion is minimal.

The term ‘mountweazel’ comes from one of the most well-known fictitious entries, that of the photographer Lilian Virginia Mountweazel appearing in the New Colombia Encyclopaedia. A similar mountweazel appeared in the form of the word ‘esquivalience’ in the New Oxford American Dictionary, defined as “the wilful avoidance of one’s official duties”. A copyright trap concerning the television series Columbo resulted in litigation between the author of The Trivia Encyclopaedia and the makers of the game Trivial Pursuit following the inclusion of the mountweazel in the game.

In a similar vein, cartographers have included ‘paper towns’ in their maps, such as the appearance of Algoe in New York, and there are suggestions that a number of paper towns have made their way onto Google Maps. However, because mountweazels are intended to trap copyright infringers their existence is usually kept secret until the copyright owner triggers the trap and the mountweazel is disclosed.

Mountweazels to the rescue

The value of mountweazels lies where independent work is likely to lead to an almost identical result. Take, for example a translation of Great Expectations: copyright in the original has expired but any modern translation into, say French, would attract its own copyright. Creating a translation requires considerable intellect and skill but nonetheless an equally skilled translator would inevitably produce a similar translation as a result of the common underlying work. One way, therefore, to help the owner of copyright in the translation to distinguish an independently created translation from a copy would be to include unusual word choices. If another translation appeared using the same unusual choices there would be a strong inference that there had been copying of the original translation.

Similarly, an anthology is simply a compilation of literary works behind which there may be a huge amount of effort and intellectual skill in choosing and categorising the selection. The method of categorisation will be dependent on characteristics of the works, be it underlying themes or dates of creation, therefore it is possible that someone could produce the same anthology through their own effort and skill. In order to guard against copying, typographical errors could be included or footnotes containing false information which would demonstrate that copying had occurred.

The key to using mountweazels is not to devalue the work through their use; they are by their very nature inaccuracies designed to catch infringers, but where the work’s purpose is to contain accurate information, such as a dictionary, inaccuracies may cause more harm than good. Similarly the mountweazels must be inobtrusive; if they are obvious then they will be recognised as copyright traps and will fail their purpose.

It is often apparent that rights owners only consider steps to help prove the subsistence and ownership of copyright or to help with its enforcement after it has already been infringed. For those creating works such as a compilation it will always be difficult to prove that a secondary work is the result of copying rather than independent endeavour. Hiding a few mountweazels in such works is a good way to spring a trap on anyone seeking to take advantage of the independent work already carried out.

All mistakes the authors’ own, and intentionally made.


This information is for educational purposes only and does not constitute legal advice. It is recommended that specific professional advice is sought before acting on any of the information given. © Shoosmiths LLP 2022.


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