Yep. Apparently if you get blocked twice, Amazon may remove your account. While in most cases, the accounts being blocked are cheaters and bots, there's always a possibility you could be blocked by mistake. And if you don't get your first block removed, and get blocked again, then Amazon may ban you from Mechanical Turk completely. If you don't appeal, or they ignore you, then any money in your account will be gone.And the end of the essay is so on point I'm just going to let him say it all (emphasis mine):
...even honest workers are afraid to work for requesters who have a history of blocking. And, unfortunately, they should be until Amazon decides to take worker concerns more seriously.
If you've gotten this far, you deserve a medal for your patience and stamina. You've also shown yourself to be someone who cares about worker rights. Even if you haven't been personally affected by the blocking system (yet), I encourage you to send Feedback to Amazon and let them know you are concerned about issues like these which have the potential to hurt honest people -- not only workers, but even the requesters whose money makes MTurk possible. Feel free to send Amazon a link to this series if you'd like.
You can also make a difference by joining in the global conversation about MTurk in fine places like this. You don't have to write long-winded treatises like I do, because even a small note here has the potential to help many others. Perhaps the words we write now will influence for the better the way Amazon chooses to operate in the future. MTurk is still a diamond in the rough, but with some refinement has the potential to be truly great.