In the real world people do not have the ability to communicate over any sizable distance on their own. To make up for this people have always employed communications systems, whether it be smoke signals, telegraph, or satellite lasers that fire emoticons at your feet, etc.

Of course, this effect is partially recreated in game through the use of herochat and has become a staple in the civ genre as a whole. However, I believe the inclusion of messaging is undermining the effect. While herochat does remove the chaos of a world chat, and makes hearing others' conversations a matter of chance based on location, it doesn't entirely take away people's ability to communicate over long distances.

This is a problem for a server trying to create a realistic environment for the development of civilizations. A brief look at human history will show that communications and communication networks have had immense impacts on the development of civilization. The very thing that makes us human, culture, is relayed through verbal and non-verbal communication. Its that important. The fact that players can just /msg anyone completely bypasses this critical element in the development of societies.

My proposal is to remove the ability to message other players in any form (as well as really cut down herochat range, but that's more personal preference) and provide ways to create long distance communications systems based on a tech tree.

For example, the lowest tier being able to write on a sheet of paper, but have limited space to write compared to a book. Higher tiers might be some plugin based around redstone that allows for the creation of telegraphs, telephones, and beyond. Have send/recieve blocks that when accessed bring up a text box in which to create the message. Telegraphs would have to be linked together and just display all messages when accessed. Telephones could be wireless but work similarly to telegraphs interface wise. Beyond could be direct messages to someone without a receiver block but the person receiving the message can't respond. (I suppose this could be extended to mobile radios, but balancing would be difficult I think.)

I would predict players would make their own communications systems around the early methods like mail, and the later game being a world covered in telegraphs and phones. The game changing elements are crazy though. Common practices like talking to someone who's been pearled become complicated affairs. The potential ramifications are pretty significant.

Obviously this is all by-passable through the use voice chat services and reddit. Although that's more of a greater problem in the experiment due to influences from the development of server culture as opposed to local culture in game, and internet/gaming culture all seeping in creating a preformed experience.