We can set aside FOIA which is a federal law and does not apply to Washington state records. The Public Records Act is what matters. Various records kept by the government must be disclosed upon request:
(RCW 42.56.070) Each agency, in accordance with published rules, shall
make available for public inspection and copying all public records,
unless the record falls within the specific exemptions of subsection
(8) of this section, this chapter, or other statute which exempts or
prohibits disclosure of specific information or records.
We have to scrutinize the information to see if it is a "Public record", which
includes any writing containing information relating to the conduct of
government or the performance of any governmental or proprietary
function prepared, owned, used, or retained by any state or local
agency regardless of physical form or characteristics. For the office
of the secretary of the senate and the office of the chief clerk of
the house of representatives, public records means legislative records
as defined in RCW 40.14.100 and also means the following: All budget
and financial records; personnel leave, travel, and payroll records;
records of legislative sessions; reports submitted to the legislature;
and any other record designated a public record by any official action
of the senate or the house of representatives. This definition does
not include records that are not otherwise required to be retained by
the agency and are held by volunteers who: (a) Do not serve in an
administrative capacity; (b) Have not been appointed by the agency to
an agency board, commission, or internship; and (c) Do not have a
supervisory role or delegated agency authority.
For the sake of concretization, I assume the information was written and prepared by a government agency. We therefore don't care where it is stored.
The request is made to the agency (not to an individual), and the agency has (by law) published procedures for processing requests (RCW 42.56.040). Perhaps the police officer in Ione (produced "Eye-own", stupid sans serif font doesn't distinguish l and I) issued an e-ticket and discovered that he filed the citation on some unofficial off-site storage facility. He still has to comply with the records request – a separate question is whether he might be punished for improper records maintenance. Storing information off-site does not create an exemption for the disclosure requirement. He cannot be penalized if he tried but failed to obtain a copy for disclosure (RCW 42.56.060).
I guess the scenario is then further complicated by an the record being controlled by some third party which the agency has no control over (me, for example), and I refuse to provide a copy of the record. Then can the government agent hack into my computer in order to obtain the desired information, in satisfaction of the records request? Without a warrant, no, and that is independent of state law (it is illegal to hack into my computer, at the federal as well as state levels).
The main problem is that public records have to be maintained, and can't be offloaded to private locations where they can't be accessed in order to satisfy a public records request.
As an example: another (private) organization has the records on a private server or private shared drive, the employee has access to that drive due to an oversight by the company, and the employee is aware that the private company has not consented (and would not consent) to their accessing the records for the purpose of fulfilling the records request. Such a scenario would seem to fall in a gray area in which computer trespass law prevents the employee from providing the records but public records law requires the employee to provide them. See RCW 40.14.020.