zed that the "permanence and absolute exclusivity" of the physical occupation at issue in Loretto "distinguish[ed it from [the] temporary limitations on the right to exclude" at issue in PruneYard. The Court also distinguished PruneYard on the grounds that the invasion in that case was "temporary and limited in nature" and that "the owner had not exhibited an interest in excluding all persons from his property." Loretto, 458 U.S. at 432, 434, 435 n. 12. Moreover, in PruneYard, "the owner had already opened his property to the general public, and permanent access was not required." Nollan, 483 U.S. at 832 n. 1. For a recent analysis of PruneYard, see Epstein (1997). Addressing the cable company's argument regarding the small size of the equipment it installed, Justice Marshall quipped, "whether the installation is a taking does not depend on whether the volume of space it occupies is bigger than a breadbox." Loretto, 458 U.S. at 438 n. 16. Networks in Telecommunications The Court was careful to emphasize that its holding was not at odds with the "substantial authority" upholding the state power to restrict an owner's use of his property. Citing Penn Central, the Court observed that "[s]o long as these regulations do not require the [property owner] to suffer the physical occupation of a portion of his building by a third party, they will be analyzed under the multifactor inquiry generally applicable to nonpossessory governmental activity" (458 U.S. at 440, 441). The reference to Penn Central indicates that the Court was referring to traditional regulatory takings doctrine. Loretto thus established two principles that play a central role in our analysis. First, the opinion articulated a strong rationale for subjecting physical takings to the highest degree of protection under the Takings Clause. If a regulation requires a property owner to allow third parties to install permanent equipment on his property, it constitutes a per se taking, regardless of the size of the physical invasion or the public purposes that th