Of course. But that would normally only be of interest to articles that you buy. Not the free types that require a link at the bottom.. These are then not the property of the person who places it on his/her site – so you would definitely need express permission to change the wording.
Paid for articles are not generally the problem.
Unfortunately, it is like that with google especially. It see all those sites with the same article as duplicate sites. Things like press releases etc.
So, should you wish to ersue this, make sure that you allow people to alter the wording of the articles and I would really suggest you do not use it on your own site, because many webmasters would take the time to change it.. and it would be bad to get penalised for duplicate content when it was yours – especially if you are looking to get an advantage for the links that you will receive.
Hope that all makes sense.
It is just that we have been dealing with duplicate content issues almost all year now.. sometimes it was stolen from our site.. but most of the time, it was as simple as a press release that 100’s of other sites also have.