It would be good if messenger plus's log files stored the images that are embedded in the messages because if someone writes a message to you though a pen connected to pc then the message is stored as an image (not encrypted in the "images" folder and makes the whole idea of file encryption pointless.

I don't think think the encryption system would work. Afaik, it's text only/

Hmm, I suppose you could encrypt the pen image, though you would have to change the filename to .txt and then encrypt, and then when decrypting change the filename back.