The Palantiri consistently provided their users technically accurate intelligence that lead to disastrous strategic decisions.
Denethor committed suicide out of despair, after a palantir showed him the black fleet approaching, but he did not know that it was actually Aragorn who had captured the fleet and was coming with reinforcements.
We don't know specifically how the palantir deceived Saruman, but it's pretty clear it was one of the key factors in his corruption and downfall.
And even Sauron himself was misled in this way! The palantir showed him, correctly, that a hobbit and Aragorn were at Helm's Deep, and he concluded that Aragorn had the ring. So he prematurely moved his armies out of Mordor and left the plains and Mt Doom unguarded, which permitted the destruction of the ring.
I honestly can't think of a worse name for a company that provides intel for strategic decision making.