Deceit comes in many forms, from the subtle to the overt. Subtle forms of deceit include misrepresentation and other diversionary tactics. More overt forms include hypocrisy and outright lying. Another form of deceit is stealing. As stated by the Watchtower Society, stealing (specifically, plagiarism) is to be considered one of the fruits of a false prophet referred to at Matthew 7:15-20.¹

Given its gross history of false prophecy, it's not as though anything else is necessary to convict the Watchtower Society as a false prophet; however, since they themselves have identified plagiarism as being a "fruit" of a false prophet, their own plagiarism ought not to be ignored.

Consider the following example of the Watchtower Society having plagiarized artwork for use in the September 15, 1982 issue of The Watchtower magazine:

The details of this particular case, including documentation from the copyright owner of the artwork, can be found at this site.

In a second example, artwork is taken from The Bible Story by Arthur Stanley Maxwell (published 1955) and used in the Watchtower Society's My Book of Bible Stories (published 1978):

Details and more examples can be found at this site.

In a third example, artwork is taken from the cover of the German magazine, Stern,² for use in the 1982 Watchtower publication You Can Live Forever in Paradise on Earth:

Click here to see a scan of page 93 of the Watchtower publication, You Can Live Forever in Paradise on Earth containing the Stern cover art.

A fourth example is one I discovered myself while flipping through The Golden Children's Bible (published 1965). I immediately recognized artwork from the Watchtower's My Book of Bible Stories (published 1978):

Additional examples of artwork taken from The Golden Children's Bible and printed in My Book of Bible Stories can be viewed here.

Plagiarism has been identified by the Watchtower Society as a fruit of false prophets; and every such "rotten tree" is to be "cut down and thrown into the fire."³ Moreover, plagiarism is illegal.  Far from being the act of a "faithful and wise servant of the Lord",⁴ it is stealing and is explicitly condemned in the Bible: "He who has been stealing must steal no longer" (Ephesians 4:28). The biblical position on stealing is no secret, and the seriousness of stealing has been acknowledged by the Watchtower Society numerous times:

Anyone who makes it a practice to lie or steal cannot have God's favor. –Knowledge That Leads to Everlasting Life, 2006, page 120.

If a dedicated, baptized Christian renews any stealing that he did before his conversion or he takes up stealing, he is assailing the name of his God. Since he as a stealer cannot inherit God's Messianic kingdom, he comes under the divine curse. This will mean his destruction, for if he fails to gain entrance into the kingdom to which he is called, there is nothing else left for him. –Paradise Restored To Mankind-By Theocracy!, 1972, page 211.

The seriousness of the matter is emphasized by this word of warning: "Do not be misled. Neither fornicators, ... nor thieves ... will inherit God's kingdom. –The Watchtower, January 15, 1982, page 4.

Those who practice stealing "cannot have God's favor"  and "cannot inherit God's Messianic kingdom".  What, other than a pre-existing, personal bias would prevent one from applying these words to the Watchtower Society? (Proverbs 20:10)