Would it work for you if the last-posted-date was fuzzier for people not the user? E.g "a day ago" "within the last week" "within the last month/two months/n months" "within the last year/two years/n years", plus "about 400 journal entries" or "about 700 journal entries" or "about 27,200 journal entries"?
Does the information have to be completely hidden?