Hackers play Space Invaders on Belgrade billboard in security stunt, are gifted with iPads (VIDEO)

Two Serbian students who broke through a Belgrade billboard's security apparatus and played Space Invaders on it were rewarded with iPads in gratitude for pointing out how easy it was to hack into, according to Ars Technica.

Belgrade citizens were caught off-guard by the 20-minute billboard stunt earlier this week, conducted on the iPhones of the two students, Ivann Petrović, 21, and Filip Stanisavljević, 20, said Ars.

They polished things off with the message “Hacked4Fun,” which was displayed alongside the logo of torrent provider Pirate Bay and a Ghandi quote reading: “First they ignore you, then they laugh at you, then they fight you, then you win," according to Torrent Freak. 

The billboard people clearly got the message. “[W]e appreciate the fact that these guys have, in a charming way, pointed us to this huge problem,” billboard ad company manager Slobodan Petrovic told Serbian news site Kurir on Wednesday, reported Ars, using Google Translate. “Now it is clearer than ever that we need to protect ourselves better. In more developed countries, these actions are unthinkable because of severe sanctions.”

In other words, thanks dudes. But they didn't stop there. The young men were rewarded for their efforts with two free iPad mini 4Gs, said Ars. For real. 

Pretty good treatment for a couple of hackers, although they say they're not hackers — merely electronically-savvy do-gooders, according to notes cited by Ars. 

"We are not hackers nor do we participate in any form of hacking," the two state, making a point of distancing themselves from radical hacker groups like Anonymous. "We are two computer science students who did this for research purposes only, to demonstrate the lack of security in IT systems in general."

And demonstrate they did. Watch it here: