Aerial surveillance startup Insitu surprised everyone Tuesday when it said that it would sell to Boeing, one of the world’s largest aviation firms. The company, which makes unmanned aerial vehicles (UAV), had been expected to go through an IPO within a year or two.

UAV makers have met with plenty of success in the past few years, in part because of the vast military expenditures in Afghanistan and Iraq, as well as growing markets for applications like tracking forest fires. We reported late last year that Insitu was probably bringing in about $80 million a year in revenue.

Neither the two companies or Insitu’s investors disclosed the official acquisition price, with Roger Lee of Battery Ventures, which led two rounds totaling $50 million in the company, saying only that it was a “great return, both at a multiple and IRR [internal rate of revenue] level”. However, according to the Oregonian, the price was at least $400 million.

The most interesting piece of this acquisition may not be the UAVs — although there are certainly plenty of other companies in the field, including Aurora Flight Sciences and General Atomics. But Insitu itself has implied that the surveillance aspect is the vital one, in suggesting that it might also work on vehicles for land or sea.

Lee says that surveillance startups will continue doing well. “We’ll continue to look at similar things,” he replied when I asked if the UAV field was too crowded. “The world is only getting more suspicious, and people’s interest in data is only increasing.”