After much debate and a reverse decision of the original ruling, all journalists will be able to use social media during the 2014 Winter Olympics in Sochi. The orginial decision of banning usage of sites such as Instagram and Twitter, was to forbid pictures and video clips being posted on those sites.
The Olympics is one of the most prestigious sporting events in the world and since the Winter Games are every four years, each edition is special. One of the significant things about social media is that news gets out to users very quickly and it spreads just as fast. Posting tweets or pictures could ruin events, which happened during the 2012 London Olympics due to some events being aired on tape delay.
In June 2011, NBC won the rights to air the Olympics, a move that would rake in billions of dollars and attract tens of millions of viewers around the world. The network was criticized for the move, but ratings were up significantly. The five hour time difference between New York and London (and eight hours between London and Los Angeles) made tape delay even more logical.
As a result of NBC having the television rights (and first priorities to media access), banning social media activity would ensure more viewers and protect the network. There would be less spoilers for those who would want to watch events as if they were live. However, spectators will not be permitted to bring non-professional equpment to the games, such as reflex cameras. Considering there is an even more extreme time difference this time around (9 hours between Sochi and New York), this won't be the last we'll hear about this controversy.