Q Why do you have copyrighted photos on a public domain website?
A Several reasons.

For one thing, many people use these photos for non-commercial uses. Kids doing reports, desktop wallpaper, Wikipedia, etc. So having the photos available to them makes sense, even if they aren't public domain.

Also, this site evolved over many years as a place to put my photos on-line for family and friends. Strangers kept asking me if they could use the images for their own projects, and after awhile that sort of took on a life of it's own. So even though the vast majority of the site usage is from strangers just looking for free pictures, my friends and family still use the site for seeing what's going on in my life. For me the site has many uses other than just public domain photos.

Q Is it okay if I use one of your photos for my commercial project?
A I'm not a lawyer. Read the license for the photo you want to use. If it's public domain, that means I've given up any rights to the image, and asking me if you can use it is pointless. If the picture is public domain, but contains trademarks, other copyrighted items, or people, then others may have rights that might be actionable. But probably not, and such things should be obvious. And if you are using these pictures commercially you really should have some legal savvy beyond anything I might be able to add. Don't ask me for legal advice. I won't give it.

Q Can I have your permission to use one of the photos here?
A If it's public domain, you don't need to ask me permission. Public domain means I don't have any copyright on the image, and neither does anyone else. You might think it's just polite to ask, and I appreciate that. But with many people asking every day, it can get a bit tedious.

Q I'm using one of your photos. What text should I use to credit you?
A "Photo courtesy PDPhoto.org"