[carussell]

No. Apache 2.0 indemnifies you only in relation to the patents held by contributors to that project.

In more concrete terms, if you see some project is licensed under Apache 2.0, then you can still be sued for using it, because while you may have a guarantee that its contributors won't sue you, it doesn't make anybody else's patents go away.

In slightly more concrete terms than that, if Project X causes Facebook to be sued by Corp Y because Facebook is using that project, then Facebook has no protection if it is not a Corp Y project nor have they ever contributed to it.

In real life, Corp Y is Yahoo, who sued Facebook several years ago on a bunch of patent-related matters. Facebook then went on a tear building up a war chest and crafting the PATENTS text so that it could never happen again.