The Supreme Court threw out these arguments in a 1984 5-4
decision, the "Betamax Decision." This decision held that the
VCR was legal because it was "capable of sustaining a substantially non-infringing use." That means that if you make a technology that your customers can use legally, you're not on the hook for the illegal stuff they do.

This principle guided the creation of virtually every piece of
IT invented since: the Web, search engines, YouTube, Blogger,
Skype, ICQ, AOL, MySpace… You name it, if it's possible to violate
copyright with it, the thing that made it possible is the
Betamax principle.

Unfortunately, the Supremes shot the Betamax principle in
the gut two years ago, with the Grokster decision. This decision
says that a company can be found liable for its customers'
bad acts if they can be shown to have "induced" copyright
infringement. So, if your company advertises your product for
an infringing use, or if it can be shown that you had infringement
in mind at the design stage, you can be found liable for
your customers' copying. [...]