I like the advice about commenting on the photo, too.

I am selective about the things I upload to my public tree. I won't upload photos or documents that my family and I cherish, and wouldn't want to see bandied about by strangers.

Or, if I'm on the fence about sharing a photo, the version I chose to upload will be cropped in a way that doesn't reveal the whole photo - creating a series of individual portraits from a group photo, for example - so even if people copy and re-distribute it, it's just a crop that I'll recognize as mine, and I'll still have possession of the complete original.

There's really only so much we can do - it's a tricky line that we walk between sharing and not sharing. Even locking things away is only a temporary solution - the next generations of our families will do what they think is best with these photos, documents and research. At some point we'll have to let them go, or entrust them to a careful few. I feel my responsibility as a temporary steward of those family items is to explain to others why we've cherished them, and my wish that they should be treated respectfully and with care.