Business bigwigs and Amagansett neighbors Terry Semel, the former head of Yahoo!, and investor Jonathan Sobel have become embroiled in a lengthy legal battle over Semel’s proposal to build both a primary residence and a guesthouse on his property, according to the Post. Sobel claims that the plans violate zoning laws that prohibit the construction of more than one home on a single parcel of land, while Semel alleges that the claim is frivolous and has been filed out of spite because the one-time Yahoo! honcho wouldn’t sell an adjoining portion of the land to Sobel. This conflict is the latest in series of legal kerfluffles between the two. Sobel is also suing Semel for clearing plant growth away from the parcel, while Semel sued Sobel over the removal of a fence.