As far as I am aware, you are free to sell paintings done from Google’s Streetview data, but the photographs taken by the Googlemaps cameras are copyrighted. So, you do not have permission to repost/display a screenshot of Streetview or make money from the screenshot- but your painting is your own to sell.
From Virtual Paintout’s sidebar:
"Google approves using Street View for art!
Google’s Legal Team has confirmed that artists can use images from Google Street View as reference for creating paintings and drawings, and the artists can sell these works without fear of copyright infringement claim from Google.
*One thing that needs to be made clear. If the artist shows an original view on which a painting is based, i.e. the original screenshot, make sure to keep the Google logo and copyright visible on that screenshot. No logos or mention of Google is necessary on your art itself. As an example, if you show your Street View art in a gallery and want to show the reference beside the painting, the reference would have the logo, not your painting."
So if you’re posting your painting, post the URL of your location rather than a screenshot.
I hope that helps to clear things up! Virtual Paintout is wonderful, it’s really cool to contribute and then see other interpretations of the same place. And it’s a godsend for a poor student like me who can’t afford to travel, but wants to paint different landscapes such as mountains, desert etc, that Google allow us to use their data for reference- to sell or just for studying.