No, copyrights are easy to get around. I own a business and I have submitted for patents and copyright protection.
If ACME company has a program Elmer wrote for them in 1981 in Business Basic that was designed for ACME and only ACME. Then ACME hires me to write them a program to work with their existing Business Basic, or maybe Cobol program, then I would have a hard time getting around a copyright because my application is proprietary to ACME's needs.
A good example of copyrights being violated is with SCO and Red Hat. That won't even hold up in court unless the code the was used in Linux matches 100%. If you're paying attention to this case, it's going nowhere.
In addition, programming is a langue based on existing functions and syntax so it's hard to copyright something that is already designed to do something.
Now, if you right a class that works with something very specific, for instance, a fedora hat manufacturer, then the copyright would be pretty solid. It would be odd for a class designed to handle the needs of a fedora hat manufacturer to be used elsewhere.
Also, if copyrights were such an issue, then I could write 20 different programs for FedEx, UPS, Amazon.com, Ebay, and any other company that have software development features. After I write all these programs I could file for copyright protection and then sue anybody else who used a program like mine. There are only X amount of ways for a program to work in those environments.
So my answer is YES something can be copyrighted, and NO they are not solid. I can quote the Wall Street Journal, and as long as I switch the words around or maybe use a different word instead of one they used, I can claim it as my own work.
A good code example. Using a while loop instead of a for loop. There, if I was worried about a copyright, I just got around it.
Again, I have had law classes, I have good friends who are contract attornies, I own a business, and I have delt with this stuff. Unless somebody here is a lawyer, I'd say I'm pretty credible.
What should really be discussed is software licensing, not copyrighting.