No, they're not. To quote from the linked Wikipedia article:
> the court held that sending a cease-and-desist letter and enacting an IP address block is sufficient notice of online trespassing, which a plaintiff can use to claim a violation of the Computer Fraud and Abuse Act
If someone wants to block Google, they can simply add a robots.txt entry. An IP block would work too. (Sending a cease-and-desist letter might or might not also work, but it doesn't really matter - context and intent matters in court; Google accepting the standard robots.txt as a 'go away' signal should be more than sufficient.)
