Spider-Man's exposure to the mutated spider venom induced a mutagenic, cerebellum-wide alteration of his engrams resulting in the ability to mentally control the flux of inter-atomic attraction (electrostatic force) between molecular boundary layers. This overcomes the outer electron shell's normal behavior of mutual repulsion with other outer electron shells and permits the tremendous potential for electron attraction to prevail. The mentally controlled sub-atomic particle responsible for this has yet to be identified. This ability to affect the attraction between surfaces is so far limited to Spider-Man's body (especially concentrated in his hands and feet) and another object, with an upper limit of several tons per finger. Limits to this ability seem to be psychosomatic, and the full nature of this ability has yet to be established. Spider-man utilizes this ability in his locomotion across New-York, but also has the ability to use it offensively, in a manner resembling the Mark of Kaine. Spider-Man rarely uses this ability though, due to its brutal and disfiguring effects. It also works differently, ripping off layers of skin and muscle, rather than burning it as Kaine does via the HCL secreted through his palms.
Two years have passed, and Peter Parker struggles to cope with the demands of life as a college student, a Daily Bugle photographer, and a crime-fighting superhero. But it hasn’t gotten any easier. Condemned by the press, tormented by secrets he can never reveal, forced to give up the girl of his dreams—at times the lonely burden of Spider-Man seems almost too great to bear... and the temptation to give up grows stronger by the hour.
The Iron Spider armor also has a secret override that can be activated by Iron Man in case of emergencies or if Spider-Man ever switches sides (which he does in Civil War #5). However, unknown to Stark, Peter was already aware of the safety measure and had bypassed it with his own override, Password Surprise. Perhaps most sinister, Stark discovered a way to give his own Iron Man armor a "spider-sense" based on Peter's, and the ability to give Spider-Man's sense red herrings.
As one contemporaneous journalist observed, "Spider-Man has a terrible identity problem, a marked inferiority complex, and a fear of women. He is anti-social, [sic] castration-ridden, racked with Oedipal guilt, and accident-prone ... [a] functioning neurotic". Agonizing over his choices, always attempting to do right, he is nonetheless viewed with suspicion by the authorities, who seem unsure as to whether he is a helpful vigilante or a clever criminal.