"They found that the older the social media, the more likely its content was to be missing. In fact, they found an almost linear relationship between time and the percentage lost. The numbers are startling. They say that 11 per cent of the social media content had disappeared within a year and 27 per cent within 2 years. Beyond that, SalahEldeen and Nelson say the world loses 0.02 per cent of its culturally significant social media material every day."