Climbing to the top of any of the Giza pyramids was banned in 1951. Enforcement has been lax, but if caught, one can face up to three years in an Egyptian prison, although it appears more likely that If you're a tourist who feigns ignorance of the law, punishment is simply being banned from the country for life.
Thanks to modern drone photography, actually scaling the monument is no longer physically necessary, as shown in the photos above of the "Great" pyramid, or as it's also known, the Pyramid of Khufu/Cheops.
While certainly not impossible, climbing to the top of the "smaller" of the two largest Giza Pyramids, the Pyramid of Khafre (or Chephren as it's known in Greek). has always been a bit more problematic as the original smooth casing stones are more-or-less intact on the upper quarter of the edifice as shown below:
But again, thanks to modern drone technology, we get a birds-eye view of this Pyramid as well:
This is absolutely FABULOUS!