Honest misunderstanding of copyright law
This is not unusual.  There are a lot of users of craft patterns, and even designers, who don't understand what rights are granted by copyright law, and what constitutes infringement of those rights. 

They might think that a work can only be copyrighted if it is marked with a ©.  Of course, copyright does not vest only in those documents marked with a © or that are registered, although these In dialogues about copyright with craft pattern users, we have seen this argument raised.

They might think that it is acceptable to copy a pattern and distribute it without permission, as long as they specify that the patterns is to be used "for educational purposes only and not for resale".  This arises from a misunderstanding of the applicability of "fair use" or "fair dealing".  We have seen this type of disclaimer attached to patterns distributed on the Internet. 

They might think that infringement only occurs if one makes money from distributing pattern copies.  This is not correct, as the test for copyright infringement is not simply a question of whether the alleged infringer has made a profit.  We have seen this response on mailing lists, too.

Deliberate misunderstanding of copyright law 
Unfortunately, this happens too.  Some people are perfectly aware what types of uses of copyrighted works are illegal, yet persist in carrying on their infringing activities, and even try to hide from copyright-conscious people.  We've seen a comment from a mailing list member who accesses her e-mail from her workplaces stating that if she were caught participating on mailing lists that distributed copies of patterns, she'd lose her job and the ability to work in her field.  We've seen mailing list owners share lists of e-mail addresses they suspect belong to designers or others who might "make trouble" by raising copyright issues.  Some mailing lists which were suspected of distributing infringing copies would suddenly disappear, only to re-emerge later under a different name.

In our observations of mailing lists, we've seen participants (who are either honestly mistaken about copyright, or choose to ignore their better judgment) offer many justifications for their activities--even after they were approached by a copyright owner and informed that their actions were impermissible.  Here are some of the most popular reasons:

It's not "stealing", it's "sharing".
Often, when trying to explain that copying and distributing a pattern without permission is stealing, the people engaged in the distribution activity argue that they are not stealing, but rather "sharing" the patterns with those who don't have them.  In exchange, other people who have patterns that they do not have will "share" with them.  But if the end result is that from one purchased, legal copy of a pattern, there now exist 200 more copies on the Internet available to be used by everyone, is that "sharing" or "stealing"?

It's free advertising, so why should you complain?
Some pattern "sharers" argue that publishers should be pleased that their patterns are being distributed on the Internet--increased exposure means more sales of crafting supplies.  But that's not logical--not all publishers of crafting patterns sell crafting supplies.  And this argument overlooks the fact that if the patterns are being distributed without permission, the publisher has lost control of the reproduction of its work.

Some people can't afford to buy patterns because they are on fixed incomes or your prices are too high.
This might be a justification for some pattern "sharers", but some of them betray this argument.  We've seen more than one mailing list owner insist that each member contribute patterns on a regular basis, on penalty of being removed from the list, because it was thought unfair that only a few members contributed scanned patterns for the benefit of the larger group.

It's not illegal to lend a book to a friend, so how can this be illegal?
This is a popular analogy--if sharing a pattern by scanning it and e-mailing it to a group is illegal, it must be illegal to share books as well.  However, this analogy overlooks how the book or the pattern is treated.  In the case of lending a book, generally it's the actual book being lent, and not an unauthorized copy.  But in the case of the pattern, there may not have been any permission given for the additional copy which was created when the e-mail was sent.

I have the right to do whatever I want with the patterns I bought.
This argument overlooks the difference between the user's right to handle the physical book or leaflet, and the right to copy the intellectual property contained within the book or leaflet.  In terms of the actual book, of course the user may choose to read it, burn it, or sell it second-hand.  But copying of the contents of the book is restricted in accordance with copyright laws.

You should be flattered that so many people want your patterns.
Perhaps you are, perhaps you aren't.  But this is not simply a case of imitation being the sincerest form of flattery.  At its best, the activities we're talking about are activities that may result in some loss of control over the reproduction of copyrighted works.  At its worst, these are activities which may result in lost sales.

You can't stop it from happening, so leave us alone.
On a higher level of discussion, this kind of comeback might be structured as a debate on whether the intellectual property laws we currently have in place are appropriate in an Internet society.  But usually, it's just a retort designed to discourage copyright owners from trying to protect themselves.

When I see copies of patterns on the Internet that I like, I go out and buy them, so you're not getting hurt.
Some people argue that the copies of patterns available on the Internet are inferior, and so when they see a pattern they like, they go out and purchase an original, legal copy for themselves.  That may be true in some cases, but it isn't always true.  On one mailing list, a member posted scans of pages from most of a book--a large number of patterns.  A second member posted a message in reply, thanking the first member for uploading this content--because she almost bought the book herself.  The implication is that now, this second member doesn't have to buy the book now--why should she?  She received the contents for free.