If your mother tells you she loves you, check it out.

That’s lesson one on day one in journalism school. Never take anything or anyone at their word. Get confirmation, and get it again.

We are reminded of this truism yet again as several online media sites picked up on a rumor that Flextronics would close more than 20 factories, including many in China, in response to the economic downturn.

Even at first blush, the story didn’t pass the b.s. test.

But forget, for the moment, that Flextronics, the world’s second-largest EMS company, is sitting on an enormous pile of cash and has access to credit facilities beyond most companies’ wildest dreams. And forget that, if anything, if Flex were to begin shuttering manufacturing plants, it is extremely unlikely to start by closing its low-labor-cost sites.

Instead, let’s look at how this happens. As is often the case, someone, usually in Asia, reports (or makes up) a rumor, which is then translated (and often, mistranslated) and then picked up on by the news aggregators that pose as media sites in our corner of the industry. Those sites care not a wit about accuracy, just about getting stories out (and collecting big checks). This isn’t the first time these sites have picked up a poorly sourced story and run with it. And it causes great headaches for those who are left to clean up the mess they make.

On Wednesday, Valeria Kurniawan, Flextronics senior chief director for marketing and communications business in Asia, debunked the rumors. What she should have done is sent those so-called media sites a cellphone, courtesy of Flextronics’ China factories, with a note reminding them that in business journalism, it’s always best to call first.