In Rowland v. Christian (1968) 69 Cal. 2d 108, 113, 70 Cal. Rptr. 97, 443 P.2d 561, the Supreme Court set forth the now well-known factors thought to be of some assistance in ascertaining whether a legal duty exists: [1] the foreseeability of harm to the plaintiff; [2] the degree of certainty that the plaintiff suffered injury; [3] the closeness of the connection between the defendant's conduct and the injury suffered; [4] the moral blame attached to the defendant's conduct; [5] the policy of preventing future harm; [6] the extent of the burden to the defendant and consequences to the community of imposing a duty to exercise care with resulting liability for breach; [7] the availability, cost, and prevalence of insurance for the risk involved. Generally speaking, the court may not impose a duty on the owner or manufacturer of the instrumentality where the injuries were caused by the criminal actions of a third party. The seminal case in this regard is Richards v. Stanley (1954) 43 Cal. 2d 60, 271 P.2d 23, where the defendant left her car on a public street in San Francisco "'unattended and unlocked with the ignition key in said car lock' . . . ." (Id. at p. 61.) A thief took advantage of the situation to steal the car, and, while driving the stolen car, struck the plaintiff. Affirming a judgment for nonsuit, the court emphasized that "when [defendant] left the car it was in a position where it could harm no one, and no harm occurred until it had been taken by a thief. Thus a duty to prevent such harm would involve more than just the duty to control the car, it would involve a duty to prevent action of a third person. Ordinarily, however, in the absence of a special relationship between the parties, there is no duty to control the conduct of a third person so as to prevent him [or her] from causing harm to another." (Id. at p. 65.) The Supreme Court found special circumstances present in Richardson v. Ham (1955) 44 Cal. 2d 772, 285 P.2d 269, where a contractor left a bulldozer unlocked and several intoxicated men started and drove it, and abandoned it when they found they could not stop it. The bulldozer caused massive destruction to property in its path. The court distinguished Richardson on the grounds that the bulldozer aroused curiosity, attracted spectators, and was attractive to children, and it was, therefore, reasonably foreseeable that it would be tampered with. In addition, the likelihood that someone tampering with an unattended bulldozer would know how to operate or stop it was small. The recent case of Avis Rent a Car System, Inc. v. Superior Court (1993) 12 Cal. App. 4th 221, summarizes the relevant case law in this area and points out that all cases in which liability was said to exist involved some sort of special circumstances, such as when a dealer regularly left cars unlocked with keys in the ignition to encourage the general public to inspect and test drive the cars without supervision. (See id. at p. 230.)