The explanation I've seen is that a palantir itself is value-neutral. However, because Sauron and Saruman each had one and used them regularly, using any of the

The explanation I've seen is that a palantir itself is value-neutral. However, because Sauron and Saruman each had one and used them regularly, using any of them became risky, because they were a channel through which information and influence could leak. But that, in turn, is arguably a great metaphor for the chilling effects of advanced persistent threats and abuse of surveillance capabilities by our ostensible/former allies.