This one, for instance: ESP8266 Returns 'invalid' - Cause 4
Right now, Aug 7, 2016, 8:31am EST, the Top Questions page says this question was modified 7 hours ago. But the newest time stamp on the question's own page is 8 months old.
I often read old, bumped questions with "modified x hours ago" stamps in the Top Questions list, only to find nothing new.
I'm aware that an unanswered-question bot occasionally feeds the current-question queue, but it doesn't add anything to the question or its answers. Does up/down-voting bump the question? Voting doesn't add any to the content, either, or at least what it adds is minimal and qualitatively different from an edit, comment, or answer.
Or is it something recent that has been deleted? If there is no new content, listing it as having a recent update just adds noise to the Top Questions list.
Listing an old question isn't unreasonable in and of itself, but perhaps the "modified x hours ago" is being applied too liberally.
Where do you see this timestamp? That question seems to have fallen off the bottom of the page now, so let's take a more recent example:
On the Top Questions page at 160809,1322 UTC, this question's listing says "Modified 1 hour ago, Community". But on reading the question page, the most recent change I see is stamped May 11-th.