Is there any issues with finding images on the net and using them on your site? As long as they are not other company logos or don't contain faces of people or trademarks, I don't see that websites would be able to trace this.

Obviously copying many images from one site and making your site look very similiar could be risky, but I don't see an issue with occasional image here and there.

Any comments?

I would not recommend it. Image theft is criminal offence. Always check the site's policies about their intellectual property.

And remember that Digital Watermarks can be used to track identification numbers, author information, or any other data that makes the image unique, which can be used in a case against you.

You shouldn't do it. It's a long way past a sites policies. If the person purchased the image from a stock photo site, especially one of the expensive ones such as corbis or jupiter images, then they have licensed the photo to use by one particular company, and sometimes for one purpose only. If you then get caught using the image they will come down on you very hard, as they make a lot of their money threatening people who have used images without authorization. It's actually much more risky than things like music and movie piracy (not that I condone those of course), as you are then putting the image out in a public forum, basically saying "hey look what I have!".

It's definitely not worth the risk.
If you need free images I suggest trying http://www.sxu.hu which is the web's largest free image archive which you can use legitimately - most with little restriction, some you just have to let the photographer use as a courtesy.
Or you can purchase quality images for around $1-$20 on average from either http://www.istockphoto.com or http://www.fotolia.com

One other thing worth noting - the commonly used term in the online stock photo world is "royalty free". ROYALTY FREE DOES NOT MEAN IT'S FREE. What it simply means is that you license the image once and can then use it multiple times say on your website, a brochure, business card, newspaper advertisement or whatever without paying a separate royalty fee each time. Most people would presume you can do this anyway, but it's a terms from "the old days" pre-web when photos were normally licensed for one use only.

Hope this helps

Thanks for advice. I never planned on doing this. Have you guys heard of any mojor cases of legal actions where images were used in such illegal way?