Great posts... I have asked nicely several times and I had people remove their photos afterwards. lol Other times I was wrong and felt bad for asking. So yeah, always ask nicely. Especally if they mention a Instagram, Twitter, or other site they are a part of.

I have posted something like this several times:

"Great to have you on Steemit!! Welcome to the site. I would suggest you post a photo with a Steemit sign with todays date and add a comment to your Twitter or Instagram page saying you have joined Steemit. This is a great way for you to verify your who you are. We just don't want someone getting rewarded for stealing your identity. It's really to protect you and the community."