Honesty and Square Dealing?

Irish novelist George A. Moore once said "Taking something from one man, and making it worse, is plagiarism." 

We tend to agree. 

Others, however, are building their reputations of "honesty" and "square dealing"  from the ideas and actions of others. 

First they flattered us by taking our ideas and promotions and using them for themselves.

Now, well, now they're taking logos and claiming them as their own. 

Honestly, where is the line?