Copying, where do you draw the line?

I have thought about whether or not to post this over the last couple of weeks, and have decided in the end to go ahead.  This may be a controversial post, I may end up deleting it, but for now, I would like to ask for your views on this subject, and that subject is essentially ...copying.

There have been quite a few small instances of my patterns and tutorials being used commercially (something I do ask not to be done), most of these I query with the maker and do, eventually, get removed (although you'd be amazed how many people try and deny what is glaringly obvious!).  Recently, this has been compounded by an incident on a craft forum when someone posted a copy of my Peacock.  I'm not going to link, and instead use this opportunity to talk about events from my point of view.

The Peacock was seen and admired in my photostream on Flickr.  The person involved decided she would like to make one as a gift as part of an organised swap.  Instead of being inspired by my Peacock, and coming up with her own, she proceeded (without asking if I minded) to work out a pattern, copying mine exactly, for herself.  The finished Peacock was then posted online to great exclamations of praise.  However, instantly, another crafter recognised the Peacock as a copy and emailed me a link.  I messaged the lady in question regarding her motives and also the initial lack of credit as to where the design originated (she has, as a result, now added my name).  

There are a number of reasons why this bothers me, the lapping up of the compliments over design and choice of materials (and I know there is a danger of sounding like a toddler having a tantrum, but hey, it's my design, and I was the one who spent the time working out the shape, how to put it all together, which parts should be fabric, which parts should be felted wool!), the encouragement of others to also 'work out the pattern', and the continued praise by other forum members (and indeed the forum itself as it was selected as a featured project), for what is essentially a rip off!

The Peacock pattern is indeed about to be published and can I make it clear there would be no problem in the slightest if this had been made using the pattern once it's available.  It is the fact that my design, something I had worked very hard on, and something I am attempting to make a living doing, has been deconstructed like it's free for all to use that I take exception to.  If everyone did this, the whole craft pattern market would pretty soon become defunct.

I have been concerned I'm being petty, making a mountain out of a molehill, and if you do think I'm overreacting, please say so, my reasons for posting this is to gain other views and help me get some perspective.  In the meantime, I have contacted the forum direct and expressed my feelings on the matter, although at this point they are yet to reply.

For me, it is about where to draw the line on what is acceptable and what is not when it comes to copies.  When does it move from being flattering, to just downright cheeky?

- - - - - - - - - - - - - - - - - - - - - 

edited to add - there is a fantastically written post by Erika Firm over on Decor8 covering this subject too, well worth reading.