My experience of the news/magazine industry is that unless a byeline appears with a picture, little or no effort will be made to trace the author. for instance, scanning pictures from travel brochures to illustrate holiday features is common practice. That picture is somebody's copyright, yet the chances of the author seeing his/her picture used is unlikely, let alone being able to prove it is his/hers. The editor of the offending publication can sit back and say they will pay upon receipt of invoice, knowing the chances of that invoice coming are pretty remote.....no photographer can afford the time to check every newspaper every day to see if a picture of their's has been used.
It's a far cry from days when the 10x8ins print (or tranny)with a clear copyright stamp was the only source of the published image, leaving no doubt in an editor's mind that use of this picture required payment.
It is now apparent that new technology, initially welcomed by professionals for its convenience, has turned round to bite them. New photographers, often frantic to see their work published, become the easy victims of unscrupulous editors under pressure from ever decreasing picture budgets.