1amShantanuB, I am not sure what you mean by "No body" and
"preventing you to stay" (you mean forcing....) - Just kidding. BCIS has no right to say that we should leave - they can deny GC, but they need to have valid grounds for doing so. BTW, they are not doing any favor to us - they are issuing GC in their interest (we are not in refugee or political asylum category). This country has everything to gain by giving us GC.
Anyway, I think the original point of the note is that BCIS should expedite the process and tell us whether we are eligible for GC or not - why drag the process and cause us mental agony.
YLB2, we can sue only if BCIS ever commits that they will process our cases within a given time frame. None of the notices we receive show any commitment (only estimated timeframe).