Flickr is one of the better websites for this. I've seen a few websites with CC work where uploaders barely had any profile information. A simple "I take all the photos I upload and I know what CC means" would suffice. Ironically, the one that felt the "safest" was someone who linked to their Instagram where they posted photos. Instagram doesn't provide CC info, so this person went through the effort of creating an account in a different website just to reupload their photos that are CC.
I was making some photo editing tutorials and I ran into a similar problem. I needed a photo of a person. Turns out photos of people have their own additional set of legal problems (right to one's own image). This made me very worried because surely all these photographers who are marking their photos as CC have the consent of the models, right? Otherwise nobody would be able to use the CC photos. What would be the point of a photo being CC if it was illegal to copy it anyway? I think some website had a license that said I couldn't portray the person in the photo in bad light, or something of sort, which was particularly problematic for me since I was looking for a photo of someone sufficiently ugly to make a tutorial about skin retouching.
There are people who do deliberately publish images of themselves under a permissive licence. Sometimes seen with photos for specific topics on Wikipedia (published on Wikimedia Commons). I can only guess at their motivations, but there seem to be a good deal of exhibitionists and copyleft idealists in that group.
If a photo is used on Wikipedia with the licence you need, there is a solid chance the vetting process was done thoroughly enough. For photos of a person this would the first place to look for me.
I was making some photo editing tutorials and I ran into a similar problem. I needed a photo of a person. Turns out photos of people have their own additional set of legal problems (right to one's own image). This made me very worried because surely all these photographers who are marking their photos as CC have the consent of the models, right? Otherwise nobody would be able to use the CC photos. What would be the point of a photo being CC if it was illegal to copy it anyway? I think some website had a license that said I couldn't portray the person in the photo in bad light, or something of sort, which was particularly problematic for me since I was looking for a photo of someone sufficiently ugly to make a tutorial about skin retouching.