It is so annoying when this happens and it happens way too often. I can see why she used your picture because that is one gorgeous cake but as we all know she should only be using photos of her own work.
On the few occasions that I have been made aware of this happening with my pics I have got in touch with the person and asked them politely but firmly to remove my photos and they have.
What you really need to start doing is to add a watermark to your pics. I know a determined faudster can remove a watermark but it does make life more difficult for them. I use Picmonkey to add mine.
Chin up, its a big compliment really and you can comfort yourself with the thought that if they need to use other people’s pics then that probably means that they have no hope of actually replicating such great work themselves. :-)
Julia Hardy
