In June, Facebook, which is still the most dominant social networking platform, came under fire for experimenting with the data of almost 700,000 of its users in an "emotional contagion" study. In collaboration with American academics, Facebook researchers removed either positive or negative posts in newsfeeds and found out that we are more likely to post happy status updates if our friends do. 

This is hardly surprising. But legal experts and privacy campaigners criticised Facebook for conducting a mass experiment without informing users they were guinea pigs. Facebook countered: "It was consistent with Facebook's Data Use Policy, to which all users agree prior to creating an account on Facebook, constituting informed consent for this research." Later, however, Facebook's lead researcher Adam Kramer issued a public apology: "I can understand why some people have concerns about it, and my co-authors and I are very sorry for the way the paper described the research and any anxiety it caused. In hindsight, the research benefits of the paper may not have justified all of this anxiety." 

The philosopher Onora O'Neill defines informed consent as  "permission granted in full knowledge of the possible consequences". Just how informed is our informed consent on social media? Studies show that most of us have never read the "terms and conditions" before signing up. And those who try are unlikely to make sense of the lengthy legalese they are presented with. 

Even if the terms and conditions were only 500 words long, people would be unlikely to read them. Researchers are trying to come up with graphic solutions instead. They might be icons we are familiar with, or a traffic light system, similar to nutrition labels on food packets. But the internet is more complex than that. Companies need to take responsibility and come up with ideas on how to simplify their terms and conditions. Informed consent should be a reality rather than a formality.

We worry about our online data, and even more so about the online experiences of those considered the most vulnerable — children. Parents worry their children might encounter strangers, violence, pornography, bullying, racism or websites on self-harm online. It is easy to understand calls for more internet restrictions for children. 

But we need a more balanced view on the risks and benefits for children online, argues Professor Sonia Livingstone, who was awarded the OBE for "services to children and child internet safety" this year. She coordinated the large-scale "EU Kids Online" study across Europe reveals that most children have positive experiences online, while only one in seven said something they encountered online over the past year upset them.

Livingstone says the internet poses the biggest risks for children who have psychological difficulties at home and outside the web. They need professional and parental support, including guidance on online risks. The challenge is to protect children from rare harmful occurrences, without limiting the opportunities to learn, share and develop resilience online enjoyed by the majority of youngsters.