Google is planning to put "eyes in machines" and boost computers' ability to automatically recognise people, places or objects.

The tech giant has just revealed plans to purchase a French firm called Moodstocks which builds software capable of working out what's happening in a photo – a trick called image recognition.

This buyout is likely to conclude within weeks, although it's not known exactly how much Google paid to buy the company.

"Ever since we started Moodstocks, our dream has been to give eyes to machines by turning cameras into smart sensors able to make sense of their surroundings," the French firm wrote.

Google said it would use this system to help identity pictures so they can be easily found through a search engine.

But the development is likely to stoke privacy fears, as many people are concerned that allowing computers to "see" like humans will one day enable the construction of a surveillance state in which our every move can be monitored by governments, cops or corporations. The news comes just weeks after it was revealed that Facebook founder, Mark Zuckerberg, tapes over his MacBook camera and microphone.

These fears are now bubbling over into the real world. Earlier this week, a man allegedly threw Molotov cocktails at Google Street View cars parked outside its California headquarters.

 In an affidavit, police officers said the man later told them "he felt Google was watching him and that made him upset". Renate Samson, president of the campaign group Big Brother Watch, said people should be aware of the surveillance potential of their computers.

"All connected devices now have a camera and microphone in them, often these can be turned off and on without us knowing," she told The Sun.

"Making these eyes intelligent will be great for identifying random objects and helping our smart devices to become even smarter, but not so good for keeping your personal life personal.