I have used my own photos twice, but yes I am using someone's work to entertain you with any compensation on my part.
But believe me I pride myself in writing jokes. But have on occasion used another's joke. I credited Woody Allen in one and made sure to use a photo of George Caitlin when using one of his wonderful jokes.
and as a copyright holder myself, I don't want someone making money off my property. But if I were to find someone sharing it freely I would not mind. But then again, I'm not a starving artist.