Is it illegal to buy domain names that might infringe copyright?

It's not a matter of copyright; it's a matter of trademark. If a name CONTAINS a trademark, you probably shouldn't register it. If you registered www.microsoftsucks.com, Microsoft would most likely sue you for release of the domain, and they would most likely win. Typos are in a gray area, and it may depend on exactly what you register and how you use it. www.disneysland.com wouldn't work because I believe "disney" alone is a trademark. You MIGHT get away with www.dissneyland.com, but some cases have successfully been brought against names that were intentionally used to cause confusion for unethical purposes (like phishing sites). There are trademark violations as well as "likeness" violations.