Ask Patents was specifically created to take advantage of a feature of the new AIA patent law that provides a specific ways for the public to inform the USPTO of documents they think are prior art to a pending application. It can be done yourself on line. To preserve your anonymity can be done via a patent practitioner (patent agent or patent attorney). There is a time widow that starts when the application is published. The closing is the later of the day 6 months after publishing and the date a first action on the merits is issued by the examiner. Under the AIA program the examiner is required to look at the submitted documents.
Many things can affect patentablity and future validity other than published prior art documents BUT this program is only for prior art documents. Hypothetically, an email written after filing by an applicate saying he "stold" the idea would not be eligible to send in under this program. It is not "published" and it is not something pre-dating the filing that "teaches" the invention.
In your specific case the company may be claiming a relatively narrow improvement, twist, or specific application of something that is well known. They may have already put a good list of prior art in front of the examiner in an IDS. If the application has been published you can look all of that up in USPTO Public Pair.
It you are an inventor on the patent or were involved in preparing the patent you have a duty of disclosure and candor to the USPTO. That can be discharged by telling what you know to an inventor or to the patent attorney.
I am not a lawyer (I am a patent agent). It occurs to me that you may also have some legal responsibilities to your previous employer relative to their internal information and you probably do not want to be slandering, libeling, etc. them. In this case everything they are doing may be completely proper but may look bad from where you are standing and with the information and knowledge you have.
An inventor no longer with the company might be in an awkward position. They have presumably signed a declaration stating that they consider themselves the true inventor and understand the application.