The Secret Service is purchasing software to watch users of social networks in real time, according to contract documents.

In a work order posted on Monday, the agency details information the tool will collect -- ranging from emotions of Internet users to old Twitter messages.

Its capabilities will include “sentiment analysis,” "influencer identification," "access to historical Twitter data," “ability to detect sarcasm," and "heat maps" or graphics showing user trends by color intensity, agency officials said.

The automated technology will "synthesize large sets of social media data" and "identify statistical pattern analysis" among other objectives, officials said.

The tool also will have the "functionality to send notifications to users,” they said.

A couple of years ago, the Homeland Security Department, the agency's parent, got in trouble with lawmakers and civil liberties groups for a social media program that would work, in part, by having employees create fake usernames and profiles to spy on other users.

A House Homeland Security Committee panel called DHS officials into a hearing after reports the department tasked analysts with collecting data that reflected negatively on the government, such as content about the transfer of Guantanamo detainees to a Michigan jail. The Electronic Privacy Information Center has sued DHS for more information on the program.

Employees within the Secret Service's Office of Government and Public Affairs will be using the new system, agency officials said.

Here is a full list of the software’s required functions: