The apparent designed purpose of Maltego Carbon (TM) is to map the Web and Internet understructures of websites and capture publicly available information for “open-source intelligence” (OSINT). The marketing of the tool positions it as a hacker’s tool for mostly “white hat” (defensive) purposes.  Other developers have built add-ons to this tool which enhance its “black hat” (offensive) purposes.  

The following recent official videos (with presentations by Paterva staff) provide a sense of the tool's design for its envisioned "use case" (here with a focus on attack mode).    

The most current version of the tool is now Maltego Chlorine.