Set all your Office365 appointments sensitivity to private

PrivateAppointments.js

CALENDAR_VIEW = '//' + location.host + "/api/v2.0/me/calendarview?startDateTime=1970-01-01T00:00:00Z&endDateTime=2111-10-28T13:03:38.168Z&$select=Subject"

async function turnPrivate (entry)  {
    let options = {
        method: 'PATCH',
        headers: new Headers ({
            "Content-Type": "application/json"
        }),
        body: JSON.stringify ({
            Sensitivity: "2"
        })
    }
  	
    return await (await fetch (entry["@odata.id"], options)).json ()
} 

async function fetchEvent (id) {
	return await (await fetch (id)).json ()
}

async function turnAllEventsPrivate () {
    let res = await fetch ( CALENDAR_VIEW, {withCredentials: true})
    return await Promise.all (
        (await Promise.all (
            (await res.json ()).value
           .map ((cal) => cal["@odata.id"])
           .map (fetchEvent)
       )).map (turnPrivate)
    )
}

(await turnAllEventsPrivate()).map (({Sensitivity, Subject}) => `${Subject}: ${Sensitivity}`)