A much less-unpleasant but still irritating example: at some point, on Twitter, I apparently clicked on a couple of links relating to Neil Gaiman, and something, somewhere, decided that he was *the* topic I was most interested in. It is the wildest of wild overkill -- I mean, I like the guy's work, but literally *half* of the suggestions for tweets I might be interested in are about him. I've had to make a discipline of *never* clicking on any of those, simply to avoid feeding this bug with any more evidence.
None of which says that it is *impossible* to come up with personalization algorithms that produce a better view of the news. But it's a good reminder that the ones we have are, by and large, still mostly pretty terrible...