In Hart v. Superior Court (1971) 21 Cal.App.3d 496, an investigating officer went to an adjoining yard and "'looked through a 1/2 inch area separating the wood planks of a fence and personally observed thirty marijuana plants five to six feet in height'" growing in the petitioner's backyard. He obtained a search warrant based upon this information. The appellate court rejected petitioner's claim of impropriety by stating, "Here, the plants were plainly visible to the neighbor and to the officer whom he invited to his premises to make a similar observation through the fence. Under these circumstances, an expectation of privacy was not reasonable." ( Id., at p. 505.) Critical to the result in Hart was the fact that the neighbor had initially seen the marijuana plants by looking through the fence and that he merely invited the officer to obtain the same vantage point from his property. ( Id., at p. 498.)