Last week I wrote about visiting the Anthony McCall show at the Adam.
While I was there, two art students (well - that was what I thought, anyway) were rather self-consciously playing with the light-streams. It reminded me of this post on the Walker Art Centre's site, announcing a forthcoming event focused on David Lamelas' 1967 work Limit of a Projection 1.
On one of the museum's Target Free Thursday Nights, visitors were invited to have their photos taken under the spotlight. The images were then posted to a Flickr set.
It makes me wonder how many 'guerilla' portraits are already out there ....