The palantir of the novel weren't surveillance tools. They were a party line, the Gondorians used them to talk to their various outposts throughout middle earth, the three we see in the movies (there may be more in the books, it's been a long time) were at Isenguard, Minis Tirith and the Palantir of Minis Ithil (now Minis Morgul) that Sauron took to Baradur.

When Sauron took Minas Ithil and captured the Palanir that was kept there the Kings of Gondor forbade the use of them. It is shown that Sauron can use them to corrupt and read the thoughts of the other users. We also see him use them for their intended purpose when he conspires with Saruman.

All to say Peter Thiel doesn't understand Lord of the Rings.