Hmm.. never had the insecure content warning. There must be a way to block that message for mturk. Yeah, many HITs that are posted here end up dying quickly, mainly because they pay well and they are the most desirable. I like to keep the 'new' section of HWTF open in a separate tab all day and periodically refresh the page. I even click on links that have been crossed out, since occasionally they come back. Other times it's a HIT that you've already done and you'll get that message too.

The whole system is a bit weird, and I've found that you have to get lucky some times to make the most money. There was an $8 HIT for only a few minutes of time up here the other week, and I just barely missed it. This is a frustrating way to make extra money. But keep at it, I made $150 last month by only doing the best HITs and not devoting too much time.

Good luck!