http://www.npr.org/blogs/thesalt/2014/11/14/363835596/big-mayo-vs-little-mayo-which-brand-has-egg-on-its-face 

 Unilever,owner of Hellmann's brand, is suing Hampton Creek, the maker of of Just Mayo.  Just Mayo makes a spread that relies on consumer ignorance of what mayo or mayonnaise is.  Their product is an egg-free spread made from peas, sorghum and other plants.  It's another one of those new age things that isn't what it claims, kind of like almond milk, milk comes from mammals not plants.  

Mayo has long been a term used in America for mayonnaise, just as we use other shortened terms for other products.  As a producer of feed grains I want to see eggs in mayonnaise, eggs come from chickens that eat grain.  And I'm tired of all the false accusations about our food supply and farming in general.  If people want to make a living producing an alternative product let them, but they have to name their products for what they are and quit claiming false benefits.

 At the crux of the kerfuffle is Unilever's assertion that Hampton Creek's labels are misleading. The company points to a decades-old legal definition set by the Food and Drug Administration that specifies that mayonnaise must contain eggs.

"Our Hellmann's brand is made from real eggs," a Unilever spokesperson wrote to us in a statement, and "we simply wish to protect both consumers from being misled and also our brand."