According to a new study of Google search trends, searches for terms deemed to be sensitive to government or privacy concerns have dropped "significantly" in the months since Edward Snowden's revelations in July.

"It seemed very possible that we would see no effect," MIT economist Catherine Tucker and digital privacy advocate Alex Marthews write. "However, we do in fact see an overall roughly 2.2 percentage point fall in search traffic on 'high government trouble'-rated search terms." 

Tucker and Marthews asked nearly 6,000 people to rate the sensitivity of a pile of keywords—including those on the DHS social media watchword list—based on whether the word would "get them into trouble" or "embarrass" them with their family, their close friends, or with the US government.

Marthews, the head of the the Cambridge-based digital advocacy group Digital Fourth, had predicted an effect on search behavior. Tucker, a professor at MIT's Sloan School of Management who specializes in data issues, had not expected to see an effect.

But by analyzing Google's publicly-available search data, they noticed a general pattern: even as searches for less sensitive words appeared to rise, searches for the most suspicious words fell.

"This is the first academic empirical evidence of a chilling effect on users’ willingness to enter search terms that raters thought would get you into trouble with the US government," Tucker wrote in an email.

Researchers found a rise in search terms with "low" government sensitivity and a decline in terms with "high" sensitivity

While searches for government-sensitive terms dropped in the US, the data indicates only a minor drop in US-based "privacy-related" searches--the sort that might get you in trouble with friends or family (see examples below).

Outside of the US—the researchers also looked at searches from the US's top ten trading partners—they found that Google users tended to search less both on government-sensitive search terms like “anthrax” (those searches dropped by 1.1 percentage points) but also on personally-sensitive terms like “eating disorder” (those searches saw a nearly 1.6% decline), even as less sensitive terms showed a general rise. The trend was led by searches in the United Kingdom and Canada, and, to a lesser extent, by France, Mexico, Japan, Brazil and China more http://motherboard.vice.com/read/nsa-chilling-effect