I have been working at my job for over a month and the other day when I went to work I noticed that the "Help Wanted" sign was posted up in the window again. I though it was unusual so I asked my store manager if that meant that I was going to be replaced and he said that he didn't think so. I asked my co-workers the same thing and they all said that they didn't know anything about it. While working my shift last night a regular customer came in the store and pulled me aside and told me that my store manager had told him the previous night that I am getting fired after they find someone else to replace me. Have my rights been violated by them telling this information to a customer and lying to me about it?

In one word - no.

Exception would be if a class of employee was being let go; for example, all blondes.

What rights? You only worked there a little over a month. You were still in the "training period."

Also, most areas are now work-at-will, which means you can quit, or they can fire you at any time for little or no reason at all.

I agree with the others, you have no rights in this situation. If you think you can improve your performance in some way and reverse their decision, go for it. Personally I would just start looking for a new job. Best of luck to you, either way.

They are a poor place to work, the manager has no class
( if that is even true what the person said) Are you still working ? Are have they fired you ?

But no they can do that if they wish, there is no"rights" about it.