"There is simply far too much evidence not only of the existence of the Danites, but of the specific murders and assassinations carried out by thugs whose names and characters we can identify. One of the most notorious, Bill Hickman, who eventually fell out with Young, collaborated in 1872 with an anti-Mormon journalist to publish his confessions of many a murder and robbery ordered by the Prophet, under the lurid title Brigham’s Destroying Angel. And from 1838, within weeks of the founding of the secret society, a text survives in which Smith himself sums up Avard’s clandestine orders to his Danite captains. Among other duties, they were instructed “to go out on a scout of the borders of the settlements, and take to yourselves spoils of the goods of the ungodly Gentiles” and “you will waste away the Gentiles by robbing and plundering them of their property; and in this way we will build up the kingdom of God.”
In the middle of 1838, Missouri settlers indeed began to complain of goods and livestock stolen, of barns and houses burned. (David Roberts, Devil’s Gate: Brigham Young and the Great Mormon Handcart Tragedy, 2008, pages 50-51.)
So, the "Danites" avengers of Joe Smith and the Mormon cult were to rob the "Gentiles" (that would be non-Mormons), plunder them and deprive them of their property to "build up the kingdom of God." And these duties described by Joseph Smith himself. I wonder if the Mormon missionaries share this little tidbit of Mormon history with all those "Gentiles" they are approaching with their "restored" gospel. Given the murder and robbery the Danites were ordered to do by the "priesthood" leaders, one might call that which was "restored" Satan's "gospel." Seems to me the cult is still "plundering," but in a more civilized way.
This is most likely the portion of Joseph Smith's journal which is referred to in the quote above:
July 27th  [For] Some time past the brethren or Saints have come up day after day to consecrate and to bring their offerings into the store house of the Lord to prove him now herewith and se[e] if he will not pour us out a blessings that there will not be room enough to contain it. They have come up hither. Thus far, according to order /revelation/ of the Danites. We have a company of Danites in these times, to put right physically that which is not right, and to cleanse the Church of every [very?] great evil[s?] which has hitherto existed among us inasmuch as they cannot be put to right by teachings and persuasyons. This company or a part of them exhibited on the fourth day of July [-] They come up to consecrate, by companies of tens, commanded by their captain over ten. (An American Prophet’s Record: The Diaries and Journals of Joseph Smith, 198, Scott H. Faulring, editor. Brackets retained from the original.)
Joseph Smith knew of, and supported, the evil acts of the Danites to "put right physically that which is not right." Jesus told Peter to put away his sword, but Joe Smith unsheathed his and ordered others to do so. And where are these Danites today? What are they "putting right?" God said revenge was His, but Joe claimed it for himself!
(above info gleaned from: http://blog.mrm.org/2010/01/danites/ )