In the case, U.S. v. Nikolai Bosyk, the US Fourth Circuit Court found that a single click of a link could justify a search warrant and seizure of computer equipment. The ruling was announced on August 1st of this year.
The case involve child pornography and the click of a link to that pornography from an IP address associated with the defendant. The Court found that sufficient for probable cause for a warrant.
Note that the statement doesn’t address whether the defendant intended to access the link, or whether he was the person clicking on the link. That apparently doesn’t matter.
The object lesson for all Internet users is to be very careful. A single click, intentional or otherwise, can allow police access to your home and computers. Be very careful.