Registering and protecting your intellectual property...

Is easier than you think. In the United Kingdom, as soon as your design is made or designed and recorded in a tangible form, you own the copyright.
The down side of selling on sites such as etsy, is that now and again, some cheeky **** will copy your work. The upside of selling on etsy IP wise, is that your designs are dated and recorded, assuming you've sold any, in your sold items.
So there you have it - strike one - copyright. United Kingdom copyright is valid worldwide and this is your first line of intellectual property body armour.
Next up: Registering your design.
I was terrified of this for some reason. I though it would involve endless forms and thousands of £... Not true.
If you are in the UK, you can check out how to register your designs here:
http://www.ipo.gov.uk/
You can get a form to fill in here:
http://www.ipo.gov.uk/df2a.pdf
and there are guidance notes about filling it in properly here:
http://www.ipo.gov.uk/df2a-notes.pdf
If you need help with it, you can call them Mon-Fri office hours on 0300 300 2000
It is really not as difficult as one might imagine. You fill in a short form, add photos or drawings, and that is that.
This service is here to protect you, the designer, and safeguard your interests, and your property, worldwide against intellectual property theft. Don't stand for it! How much do you value your design? It costs from £60 to register a design. It is money well spent.
The next part of your defence could be to join a body like ACID. For a small business, this will cost you around £175. Upon joining, you get an hour's free legal advice per problem, as well as having access to network of specialist solicitors who will give you discounted rates.

So what should you do if you think someone is copying your work?

The first step is to gather evidence. Do this before you contact them. Take screen grabs if they are selling online, and gather as much evidence as possible. Get good legal advice and find out for definite that your design is being copied. There are some really good guidance notes about that here in the ACID application brochure if you are unsure. They dispell some myths, such as the idea that if someone slightly changes an element then it is no longer considered copying. This myth is not true.
Next, ask them to stop. Tell them to remove from sale immediately all your offending material. You can also call them out publicly on sites such as you thought we wouldn't notice if you choose to.
If that doesn't work, send the legal dogs in if you have the funds to do so.

I will not tolerate dishonest, shameless, sneaky people who want to rip off my work, and if you're a designer, neither should you.
If you're reading this and you have copied, or intend to copy my work, beware. Most of my designs are registered or have registration pending, and I will have no hesitation in sending in the rottweilers.
Would you tolerate someone stealing your purse? Would you think it was OK to steal money from a stranger? When you steal someone's intellectual property, you are doing just that. It is not fair, it is illegal, and I will not put up with it. Don't get me wrong, I'd much prefer that the fluffy world of etsy was as fluffy as it seems and we could all play nicely with the other kids. But when one of those kids steals my designs, I just will not tolerate it.