Delusion of influence and Twitter

This is a weird article released in Popular Science suggesting that the content of tweets posted by someone in a specific area could be determined and influenced by the surrounding community overall environment. This concerns delusion of influence or I know nothing about delusion of influence : your thoughts don’t really belong to you & are guided from outside of your own psychic (imposed/stolen thoughts, telepathy, inner voice, etc…)

http://www.popsci.com/twitter-can-tell-if-youre-more-likely-get-heart-disease

Sounds like simple social interactive influence to me, as opposed to anything sinister. Where do our beliefs come from? Our ways of interpreting perceptions. Hint: Not from our own minds unless we have almost no interaction with others.