Some time in 2000, a concerned mother discovered a log of chat room conversations between her under age son and a stranger. Worried, she notified the police.
The stranger turned out to be a registered sex offender, and, on October 11, 2000, Sgt. Brook Thomas Schaub of the City of Saint Paul Police Department asked his ISP, Yahoo, to keep an archive of his transmissions. Yahoo complied.
Some time later, the police department faxed to Yahoo a copy of a search warrant. Yahoo's employees retrieved the relevant information, and forwarded it to the police.
When the case went to trial (US v. Bach), however, United States District Court Judge Paul A. Magnuson found the execution of the warrant "defective". Sgt. Brook Thomas Schaub should have been physically present during the warrant's execution, the Judge wrote, and his absence "when the warrant was executed amount[ed] to a violation of both federal and state law that implicates the Fourth Amendment of the Constitution".
After the ruling, Yahoo objected to the possibility of having on its premises unpredictable numbers of police officers executing search warrants.
The 8th Circuit Court of Appeals in St. Louis has overturned the lower court's ruling. Police presence during the execution of a search warrant at an ISP is not required.
Reuters reports here.