What constitutes plagiarism?

Occasionally I run across job ads where the client wants writers to simply reword existing articles. The idea is that they want to "borrow" these articles...without Copyscape or other copy-protect programs picking up their "loan."

Although some people — specifically, the clients that post these ads and the writers who answer them — don't consider this plagiarism or copyright infringement, I disagree. Even if you play musical chairs with the wording, the "new" article is still pretty much the same work, just wearing a dime-store disguise.

While researching an article for a client, I ran across a prime example: an article that was "borrowed" from two existing articles, both of which ranked on the first page of the search engine results. (In other words, the "writer" didn't spend very long "researching.")

Here are the two articles that were borrowed from:
http://ezinearticles.com/?Want-To-Consolidate-Credit-Card-Debt?&id=80580
http://www.bankrate.com/brm/news/cc/19990329.asp

Here is the plagiarism:
http://www.brajeshwar.com/finance/badcredit/consolidate-credit-card.html

If you read through all three, you can see that the first article is copied sentence for sentence — if not word for word — in the third article. The second article is not copied quite so closely, but I think it is still arguably plagiarism, as all of the main points — and some similar sentences — are there.

I actually come across these things quite frequently in my research for this client — I guess his topics are popular ones. I have noticed that one of the hallmarks of these "borrowed" articles is poor English. Often, the words are replaced with synonyms that are close in meaning but not exact, and the sentences are rephrased so that they don't quite make sense anymore. Sometimes an extraneous "a" or other short word is inserted into a sentence — seemingly a typo, but I actually think it is either 1) intentionally placed to fool Copyscape, or 2) an indication of how poor the "writer's" English really is.

My opinion is that, no matter how you replace words or rephrase sentences, if you are copying an article point by point then it is plagiarism and copyright infringement. In fact, I would say that if you only have one or two sources, then you are in serious danger of plagiarizing, even if it is unintentional.

What are your thoughts?