I cam across a data visualizer that looks a lot like the pageview analysis tool [1].  It shows the frequency of words in comments on reddit.com: the n-gram visualizer [2].  If only that dataset was public ;-)


[1] https://tools.wmflabs.org/pageviews/#start=2016-01-31&end=2016-02-19&project=en.wikipedia.org&platform=all-access&agent=user&pages=Cat|Dog

[2] http://projects.fivethirtyeight.com/reddit-ngram/?keyword=global_warming.climate_change&start=20071014&end=20150831&smoothing=30