Article: Yellowstone National Park addresses rumors of earthquakes, eruptions, and evacuations
Bad news is more fun that good news.
Panic sells more than peace.
People are hard-wired to pay attention of danger.
People like being scared, when that which is feared is obviously not really dangerous: roller coaster rides, slightly too fast driving, spicy foods dares, etc.
On the other hand, when that which is feared is actually dangerous, people often switch from the truly fearful thing, and place the fear on something that is not likely to happen. This is a psychological defense mechanism. It is helpful for a short period of time. Longer, and it becomes maladaptive.
This same mechanism also explains why we, in the midst of a crisis, tend to blame our failures on others. In the short run, it is adaptive. In the long run, we have to take responsibility for our failures.
Islamic fundamentalism and it associated terrorism are truly fearful. However, many people went crazy about George W Bush instead (even the sufferers called it "Bush derangement syndrome') or about Christians ("The coming Christianist Theocracy!!!11!" They are going to outlaw tampons!!1!). [Both are actual outbursts of hysteria that occurred during the Bush Presidency.]
Global warming exploded as an issue in the aftermath of 9/11. Displacing fear from a real horror to an imagined, or at least a distant one, certainly explains some of the intense emotional reaction that surrounded global warming.
Yellowstone is an active caldera (so is the Bay of Naples, of which Vesuvius is a part). It is expected to "breath;" to go through times of expansion and contractions, swarms of earthquakes, etc.
And, for the time being, that is all that Yellowstone is doing.