It's probably someone with a browser cutting and pasting your copy.
I agree. We call these types of distributors 'trunk slammers' (mostly because before the advent of the web, they sold their products from the trunk of their cars and offered zero after market support). Most of them are not too bright and would view automated copy theft as something akin to reading ancient Greek.
One of the strategies we've adopted to thwart unwanted viewing of our product info is to offer preferred customer discounts and require login before we serve up the goodies. On the stuff we do allow the general public to view, we pepper the HTML with custom tags and CSS class ids. You'd be surpised how infrequently the thieves bother to remove something like <p class="DD15893wankerbeans"> text </p> -- more proof in my mind that they are not too sophisticated in or concerned about their thievery. Hunting down stolen text is simply a matter of creating our own robots to search out these custom class names.