estopped

Even if it is, I imagine Facebook would respond that the suit is equitably estopped by laches (unreasonable delay in enforcement of a claim).

You're not estopped by someone else's failure to enforce their own rights, independent and unrelated to yours.

If you challenge in any of the post-grant proceedings, you'll be estopped from suing on anything you raised or could have raised.

At best the authors are estopped from bringing suit but even that is unclear.

Microsoft is estopped by law from asserting patents on C#.

At that point, the US was estopped from changing course.

So your hyperbole has estopped your criticism of Bannon's hyperbole.

Unless Oracle successfully sued for openness or told somebody that it would not do this, I don't see how they could be estopped.

You won't get estopped from a trademark suit because the person who was misusing the mark thought they'd get away with it, that's completely contrary to how estoppel is used.

If we don't protect our trademark in instances like this, where we are aware of infringement, we can be legally estopped from protecting our trademark in future cases.

Courts won't buy the theory that I'm estopped.

In a case such as this, the creditor may be estopped from relying on their legal right to repayment, as the creditor has represented that he no longer treats the debt as extant.

After the war is over, the landlord would be "estopped" from claiming rents during the war period.

And transactional law is pretty damn clear on this point -- by actively encouraging the use of Mono, MS is estopped from ever suing for patent violations for the use of Mono (estopped means that b/c they have induced others to reasonably rely on statements that they will not sue for using Mono, they cannot later go back on their word b/c this would be unjust -- the court will not allow them to "trap" others).

United States, which holds that “the Government would be judicially estopped from taking a contrary position” regarding a prior representation involving the availability of relief in the form of reliquidation.

If you give permission to someone to use your mark, then you're estopped from suing, but I didn't say "Give everybody permission" I merely said there's no need to sue or threaten to do so.

If Disney allowed primary schools to do a Little Mermaid play that's blatantly just the script of the original cartoon movie, and then one day they pick on the play at Little Nowhere Infant School and decide to sue, the lawyers for the school (if it can afford them and doesn't just settle) would argue that's Estopped, there's a long standing understanding that it's OK for schools to do this.