this code is obsolete since the 2020 new facebook design. refer to: https://github.com/YoraiLevi/SetFacebookPostsPrivate make all facebook posts private(activity log) very dumb code.

pasteconsole.js

lasti=0
lastj=0
var privatefb = function(){
items = document.getElementsByClassName('_42ft _4jy0 _55pi _5vto _55_p _2agf _4o_4 _401v _p _1zg8 _4jy3 _517h _51sy _59pe')
for(i=lasti;i<items.length;i++)
{  items[i].click()
    items[i].focus()
lasti=i
}
items2 = document.getElementsByClassName('_54nh _4chm')
for(j=lastj;j<items2.length;j++){
if(items2[j].innerText == 'Only me'){
    items2[j].click()
}}
lastj=j
}
function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}
async function dopriavte() {
while(true){
privatefb()
await sleep(5000);
}
}
dopriavte()