Ask HN: Is an IP address sufficient cause to suspect people of CP possession?

No. It might be becoming more common but an IP address does not identify a person. You need to search a suspect's possessions before you can have any evidence. It might be reasonable for the police to use this lead to obtain a physical address then search for CP but an IP address along should not be sufficient.

Thankfully courts are beginning to realise this fact in regards to copyright infringement. [1]

[1] https://www.techdirt.com/articles/20140122/07375025953/court...

An IP address (which is matched to a specific "customer" MAC address or login name. ISPs do log this stuff.) is enough for probable cause and a search warrant. The law enforcement agency then executes a search warrant and finds evidence, and the case is further built off of this. If the case goes to trial, the IP address is a mere stepping stone in the prosecution's case, and not much more.

Suspect, sure. Convict, hopefully not.