'Why can't the mags have back issues on the net?' asks strafer.
There are many reasons, but the one of most significance to all of us who make our living from writing and photography is copyright. Reproduction of our material on the net constitutes fresh publication: either publishers pay for the usual first UK magazine publication rights AND first internet publication rights (something they rarely do) or they pay a seperate fee for publishing on the net. Unless they do one or the other, they are in breach of copyright law.
That said, any writer or photog can - and sometimes will - agree to net publication or waive any fee IF their permission is sought.