The problem is that the average telescope isn’t able to see things that small on the moon’s surface. Remember, even the lunar lander itself was small; everything had to fit into the nose of one of those rockets. What with the level of magnification and resolution needed in the telescope and the distortion caused by the atmosphere, I’m really not sure if even the big fancy telescopes that the big fancy observatories use could see the stuff (our friend LaMa here and his network of fellow astronerds ( 
) would probably know more about that than I do).
And even if the big fancy telescopes that the big fancy observatories use could see the stuff, then they probably wouldn’t bother. Those telescopes are expensive to use and also are in great demand with astronomers. They have some pretty long waiting lists of people wanting to use the things, and most of the things that the astronomers want to look at are only visible for a few hours a day at most. So I really, really doubt that an astronomer who has finally managed to get some time on one of those telescopes is going to be spending that time casually sightseeing. And the telescopes in orbit, such as the Hubble Space Telescope, are going to be even more so like that.
That leaves the spacecraft that have been sent to the moon since the lunar landings, such as the Galileo and Hiten and Lunar Prospector spacecraft. Of those that made the journey successfully, only a few had cameras. And many of those cameras weren’t ordinary cameras, but were instead highly specialised ones that wouldn’t take pictures like we’re used to. And of those that had cameras that took ordinary photos, they were generally set up for mapping the moon’s surface. They had resolution good enough for that, but not for seeing anything like the lunar modules.
Chang’e 1 had a resolution of a whopping 120 meters per pixel.
SMART-1 had a resolution of 80 meters per pixel.
Clementine’s camera had a resolution of at best 25 meters per pixel.
SELENE had a resolution of 10 meters per pixel.
Chandrayaan-1, which is circling the moon right now I think, has a resolution of 5 meters.
The Apollo lunar landers, which are of course the largest of the items that the astronauts left behind, have a diameter of 4.27 meters.
Notice the problem there?
We have only just recently gotten a camera there that was of sufficient resolution to show the landing sites. Of course, since it was a space program that sent that satellite there, took the pictures, and then released them to the public, and since the conspiracy theorists claim that the world’s space programs are all in on the plot, that evidence will mean absolutely nothing to the dedicated conspiracy theorist.
