updated 11:40 pm EDT, Wed May 16, 2012
Likely purchased for Android development team
Even though the IPO roadshow is ongoing and large acquisitions are generally unwise during that period, Facebook has purchased Lightbox. Lightbox is a predominantly Android photo sharing startup with many similarities to the recently acquired Instagram. Facebook is closing Lightbox, and likely going to use staff developers for Android development. No terms of the deal have been formally announced.
Lightbox stopped accepting new users following the announcement. Existing users have until June 15 to conclude business and download all remaining photos. Existing photos are not going to be transferred to Facebook, like Instagram's photos will be.
The founders are pleased with the move, and "happy to announce that the Lightbox team is joining Facebook, where we'll have the opportunity to build amazing products for Facebook's 500+ million mobile users." No layoffs have been announced or are expected.