For more information about how the journals work, please see Life In The Castle.
Paradisa's journal system is, in essence, the game's "network." It connects everyone in game together via individual magically-linked journals, which can transfer both sound and writing. Though the journals pick up pencil and crayon as well as ink, it can also transfer any other kind of liquid -- water, alcohol, blood, etc.
Because the journals are magical and not technology, there is no way to "hack" the journal.
USING THE JOURNALS
All journal posts go in the paradisa community. Old (pre-Dreamwidth) entries can be viewed at paradisalost, which is a separate, IC journal, though only residents who were around before 2012 will have them in their possession. Copies can be ICly found in the castle's library.
Journal entries must be either dictated or written/drawn/scribbled/etc. There is no "video" function. The journal transcribes anything spoken into text for easy perusal if a character doesn't happen to have their journal open at the time an entry is being made, or if they want to re-read something later.
For characters who are blind or illiterate, the journal may also read aloud entries that are written. Paradisa's magic is known to be temperamental, though, so it's up to you if this happens.
All characters automatically write in Paradisa's "common tongue" without thinking, making their handwriting mutually intelligible to one another. They may consciously write in another language (providing they already know it!) in which case the journal will not automatically translate for anyone else.
Posts or parts of entires may be filtered to individual characters or to groups. There may be multiple filters per entry. Your character doesn't need to know the other character's name in order to make a filter; "filter to John Smith" works just as well as "filter to this guy" or "filter to everyone who doesn't like ham."
Filters cannot be "hacked," as they are magical in nature and not technological.
LOSING THE JOURNAL
The journal doesn't want to be lost! If a character misplaces their journal or intentionally "loses" it, the journal will show up somewhere near the character no matter where they go.
IS THE JOURNAL ALIVE?
It can be surmised that the journals are an extension of the castle, and therefore have some degree of sentience. They don't communicate back to their owners or anything overt like that, but they do have a habit of falling open at inopportune times.