Considering that the FBI is a nationally recognized federal agency or entity in the US$,$ it apparently seems that accessing the private cellphone conversations and emails without any official warrant evidently falls within the legal and operational jurisdiction of the FBI, based on Section $702$ of the Foreign Intelligence Surveillance Act or FISA. However, this particular section of the act basically refers to or applies to the issues or cases pertaining to the national security breach or imperative. In other words, any section of the FISA is legally applicable to the issues or matters concerning breach of national security or poses a serious and proven threat to the national security in the country such as terrorism, embezzlement of highly confidential federal or government data, and so on$.$ In this particular case, the series of robbery incidents in stores in a large city practically constitutes an internal or specific issue or case and not a broad national agenda or issue which can harm the national cohesion or security in the country. Therefore, accessing any private data as long it does not amount to a serious and considerable threat to the national security of the nation, the sections of the FISA might not be directly applicable to such instances or incidents.

$2.$ Criminal conviction on the basis of unanimous jury verdict has been a long judicial tradition on any legal tribunal in the US$.$ Now, based on the information provided in the question, only the states of Louisiana and Oregon officially allow criminal conviction based on a less than unanimous jury verdict. However, the US Supreme Court ruled that non$-$unanimous jury verdict are unacceptable and needs to be revoked thereby implying that it would be morally wrong on unjustified for the criminals who have been previously convicted based on less than the unanimous jury verdict tp continue their conviction time. Therefore, considering that the non$-$unanimous jury verdict and criminal conviction are completely revoked or abolished by the Supreme Court, the conviction prosecution of the previously convicted criminals based on the same condition needs to be practically reconsidered and restructured accordingly at least on the ground of moral or ethical equity. Now, in this context, awarding a completely new trial for these convicts might seem practically illogical considering that their crimes have been adequately and incontrovertibly proved in the court of law previously in the presence of the honorable chief judge based on sufficient and reasonable evidence and proof. It would entail a considerable financial burden for the state to renew any old trial or start a completely new trial for the old or previous convicts based on non$-$unanmous jury verdict.