Moral Designs - Or - My Parts Match Your Parts?
I Am Not A Lawyer, but...

the usual run of intellectual property divides into these areas:


patents (government-granted monopoly of a method or system for accomplishing particular functions that are non-obvious, useful, and novel)
copyrights (right to prevent others from using identical design elements)
trademarks (government-registered brand names / logos)
trade secrets (ideas kept secret, no legal protection here)


Unless you have a patent on a particular functional piece of circuitry, or you can prove that someone else made an effort to copy widespread portions of your schematic/layout/software, it would be difficult to keep someone else from using similar circuit elements. (And the same for them to prevent you from doing so.)

Resistor dividers + capacitors probably don't meet either criterion (although the US Patent Office has granted patents for things that are more obvious), so I wouldn't worry about it.

If you're talking about more complex ideas, you should probably talk to an attorney who specializes in intellectual property law.