The Chinese, the Russians, the Israelis, and maybe the Iranians; probably not the Koreans
During the Cold War, Russia launched hundreds of spy satellites, many of them functionally identical to those launched by the United States. They crowded the space over North America and Western Europe, returning pictures and captured communications to the KGB and the Soviet military. Even now, Russia and the United States operate reconnaissance satellites over each others’ territory as a means of verifying adherence to strategic weapons treaties.
During the Cold War, China spent much of the time feeling left out and occasionally throwing crazy tantrums like the Cultural Revolution. With Russian help, they were able to start a ballistic missile program that eventually netted them a usable satellite launch vehicle (as well as, more recently, nukes capable of glassing the west coast of the United States). China has calmed down some since Mao’s death in 1976, but there are still enough Stalinist elements within the party ranks to accurately qualify the government as paranoid. They don’t have many satellites in orbit, but the ones that are there are probably spying on anything and everything they can. Modern Chinese spy satellites carry the same capabilities as American ones, packing SAR sensors, extremely high-fidelity long-range cameras, and MASINT packages.
Israel has had a lot of help from the United Sates in getting their satellite program off the ground. We’ve loaned them technology, sold them rockets, and manufactured satellite components for them. When Israeli technology breaks, American technicians fix it. When Israel needs a few bucks for rocket fuel, the American taxpayer supplies it. Israeli spy satellites are probably second in accuracy and resolution only to those operated by the United States, mostly because the ones they have are our hand-me-downs. And no wonder we so eagerly help them out—they are a close ally, and they are surrounded on all sides by enemies. Any edge they can get in intelligence could one day mean the difference between survival and total destruction. Also, they aggressively spy on the United States.
The Iranian space program is cute. So far, the largest payload they’ve managed to get into space is a crate-load of bullshit, along with what are supposedly a couple of small commercial telecommunications satellites. The low, fast orbit of the second satellite, launched in 2009, indicates that it has at least some reconnaissance capability, but Iran is nowhere near the United States, Russia, China, or Israel in technical sophistication.
North Korea took a lot of crazy lessons from Mao Zedong. Almost every word out of the mouthpieces operated by the Stalinist government sounds to the rest of the world like the outlandish claims of an imaginative third grader who thinks just declaring he’s been to the moon makes it so. North Korea claims they launched a satellite into orbit in 1998, but if they did, it’s invisible and totally undetectable.
The truth is that North Korea has very little skill in rocketry. What missiles they do have are slow, clumsy, and incapable of carrying a payload much more terrifying than a basket of pit bull puppies. If you’re old enough to remember the first Gulf War, you’ll recall the painfully embarrassing performance of Saddam’s SCUD missiles, which did little more than amuse NATO forces by blowing up harmlessly in midair or crashing into the desert. North Korea’s best rockets are reverse-engineered from the SCUD, with bigger gas tanks. If North Korea is spying on you, it’s not doing so from space.
More than forty countries operate satellites in orbit around the Earth. Any one of them could carry some amount of reconnaissance capability, and almost all of them travel in the narrow elliptical band around the equator that gives the best view of most of the planet. At any time of day or night, you are under the eye of thousands of cameras.