An Internet festival in Brazil billed as one of the biggest in the world has proved an irresistible attraction not only for corporate technology sponsors -- but also for military recruiters and politicians.
All were out in force at the third annual week-long Campus Party which closed this weekend after gathering 6,000 web-savvy "nerds" from across Latin America.
Among the areas promoting robotics, debates, computer games, design and programming were officials looking to lure the young participants to their missions.
Next to a camouflage tent bedecked with a US Marine flag, Brazil's air force had set up multi-screen, surround-sound flight simulators that officials insisted were not mere "games."
"It's more historic, to show how planes developed over the decades," said one demonstrator/recruiter, Kurt Krause, next to a 20-something "pilot" whose virtual cockpit was being strafed by a World War II enemy plane.
"We've had about 100 people a day come through, and there's been quite an interest in learning about the air force," affirmed a colleague, Andrea Krauthein.
Just a few meters (yards) away, though, a much bigger crowd was waiting for turns to play another simulator whose theme -- and popularity -- dismayed the air force team.
Those players were battling their way through a split-screen duel based on the hugely popular point-of-view shoot-em-up game Modern Warfare 2.
The made-up world they were blasting their way through to bloody effect was a representation of a Rio de Janeiro slum. One player assumed the role of a gun-toting gang warrior and the other a member of Brazil's brutal elite urban police unit.
The screen was set up in a booth belonging to the telecom group Telefonica, which was ostensibly showing off the roll-out of its new 10-gigabyte broadband offer.
One player, 22-year-old student Rodrigo Prado Morena, quite cheerfully called it "just a game" with no hidden intent, as he locked his hapless rival into "kill cam" mode before a respawn.
Elsewhere, past rows of laptops and desktops plastered with joke stickers like "If you don't follow me on Twitter, don't walk behind me" and "C:/RUN/DOS/RUN," officials from a government department were readying a presentation on how sites such as Facebook can promote human rights.
"We're reaching out to young people... We have even launched a web mascot to help fight against child pornography," explained Mariana Carpanezzi, who was there for Brazil's special secretariat for human rights.
The small number of chairs prepared for that talk, though, contrasted with the many rows already filled in front of a neighbouring podium where a talk on "Is the Internet for porn?" was about to start.
And then there were other areas pulling in large number groups intent on just having fun -- even at the literal risk of mental health.
One such was a variation on the bestselling "Guitar Hero" game. Only instead of the player standing in front of screen and strumming a hooked-up guitar in time to the music, this one featured a wireless shaggy wig as the "instrument." The aim: to shake, jerk and snap the head in time to heavy metal riffs.
Roge Delavi, a 27-year-old post-graduate student who ignored the mandatory on-screen warnings of possible "neck injury" and "brain trauma" to energetically flail his head around in front of a projected mock death-metal concert, gave his verdict.
"It's great," he said after a two-minute workout, sweat trickling down his face.
Almost forgotten up the back of the exhibition center, near the secure area where 3,000 tents had been set up to accommodate participants, a group of indigenous Brazilians from the Amazon proudly displayed their blog.
"It's a site where Indian people exchange experiences and maintain a presence in the virtual world," said Poran Potiguara, a 20-year-old demonstrator wearing traditional feather headwear, as he clicked through www.indiosonline.org.br .