If in the midst of a face-to-face conversation, a member handed you something — a paper perhaps they wrote, a picture they took, even cookies they baked — and the member said “Here, I’d like you to have this,” your response would most likely to be to thank him or her. That’s what we were raised to do. If at further glance it was something you didn’t care for, you would politely decline and if possible tell them why. That’s what polite people do so why do we treat social media and activity on our online communities any differently?
If someone uploads (non-offensive) content to your site, they are giving you something. Yes, it may be self-promotional, ill-timed, or not exactly right for what you’re trying to accomplish, but they are giving you something none-the-less. Removing their content with no mention to them as to why interferes with your relationship. The feeling derived from it is akin to giving someone a gift, turning around and catching them chucking it into the nearest trash receptacle. We have to remember that online relationships warrant the same amount of courtesy, our offline ones do.
Plus when it comes to online content, you can never have too much. If the content is not exactly what you’re looking for or if it breaks some kind of posting policy, let your member know. Maybe he wasn’t aware. Maybe she was hoping you could find some use for it. Letting your member know why you have to remove it will open up the conversation and maybe the two of you can then come up with an applicable place for the content or a compromise that will make you both feel valued and accomplished.