Online Threat Alerts (OTA) - Alerting you to scams and frauds.
Useful - Informative
Below is a list of keywords and phrases use by The Department of Homeland Security, to monitor social networking sites and online media for signs of threats against the U.S. The words are included in the department’s 2011 "Analyst’s Desktop Binder" used by workers at their National Operations Center, which instructs workers to identify "media reports that reflect adversely on Department of Homeland Security and response activities."
If you don't want to be spied on, do not use any of the words in the following list. However, I think that is impossible, because there are words like agriculture, gas, snow and many more, which are used everyday in simple sentences.