Kyle McDonald is said to have installed software that photographed people looking at laptops then uploaded the pictures to a website.
Writing on Twitter, Mr McDonald said: "@secretservice just stopped by to investigate [web address removed] and took my laptop. Please assume they're reading any e-mails you send me."
Kyle McDonald's images were uploaded to a page on the blogging site Tumblr. In the description of People Staring at Computers, the project is described as: "A photographic intervention. Custom app installed around NYC, taking a picture every minute and uploading it if a face is found in the image.
"Exhibited on site with a remotely triggered app that displayed the photos full screen on every available computer." No arrests had been made in the case as of 8 July.