Does stamping it in faint writing stating it's not for use without permission make any difference?
If someone stole one of my images and used it to make money I would be absolutely furious!
No, watermarking a photo makes no legal difference, and if you use some made up company name may hinder your legal ownership -it also screams amateur wannabe pro.
What you can do is put copyright information into the jpeg IPTC fields. Any professional commercial designer upon finding an unknown photo will check the IPTC for copyright information. Unscrupulous individuals will ignore that, and ignore any watermark anyway.
If you are really worried then the best option is to upload only a low res higher compressed image, and keep it only on a website you own (some people will search sites like Flickr to find photos they want, when everything is tagged then it makes finding the photos very easy).
Better still is not to upload that much in the first place, if it is not online it cannot be stolen. I print my best photos, make cards for friends/family, print albums and have slide shows when guests are over. I don't feel the need to share my work with random Internet people really.
Oh, I also put some of my stock orientated work on sites like Alamy and shutterstock, this gives legal protection to these photos. If I see a photo on a web page that doesn't appear to be legitimately sourced then I get free professional legal assistance to get the photo removed and sue the culprit (although I don't get any of the proceedings, nor do I pay any of the costs). I've never done this before but if you brows the forums of stock sites then you see quite a few cases of people getting legal help this way. Of course in doing this you are selling your photos for commercial use anyway, just you are charging for that use.
And this gets to my final point, going about funky means to protect your image such as plastering hideous watermarks doesn't help you at all unless you can afford to pay the lawyers to defend your work, which is why the legal protection offered by stock photography sites is quite nice. Without a good legal backing if someone or some company stole an image on purpose the best you can do is ask nicely. IF they don't comply you can try some no win no fee layer but they don't like these kinds. In any case it will come down to proving that the individual/company purposely utilised the image knowing that they did not have the rights. Their defense will be simply that they believed to the best of their ability after extensive research that it was an orphan work and free to use. I have also heard the excuse that they will claim they believed an employee took the photos and since all their employees have a IP agreement that makes all such works belong to the company then they had no reason to believe that the photo could not be used.
PS: your photo is automatically legally protected the moment you release the shutter. There is no need to do anything, you already own full copyright and legal ownership.
