Metalhead41 was lucky in that permission was actually requested.
I have today found one of my images on someone else's website. It has been copied from the website of one of my cricket clubs (the only place it should be found) without permission and has had all the EXIF/IPTC tags expunged, including the "Copyright ... all rights reserved" one. No credit is given.
I am not looking for payment if the image is used in appropriate context (it is). In fact, with prior permission, and with both IPTC tags and a credit to the cricket club website in place I would have been delighted for them to use the photo and would have let them have a high resolution version of the image to work from. But they did not, and so I am angry.
I am not sure how best to pursue this.