One (often illegal) form of recreational tourism is Tormentor Tours
A jaded citizen Zar might, with difficulty, find a Cyberian or Discordian holiday company which will project them into a lo-tech prim world, virch or societum with the express purpose of creating mild havoc; appearing to the inhabitants as spirits, mythological figures, aliens from the unknown deeps of space, time travellers from the future. The Tormentor Tourist could set eirself up as a god, or in extreme cases, a monster or devil.
Most often these intrusions occur with the collusion of the controller/caretaker of the low-tech world; it is difficult for any entity to gain access to such world without such permission.
Most low-tech reserves are kept free of outside pollution, in order to allow the prim world to develop in its own way, and perhaps develop new perspectives on the universe. However a reasonable proportion are deliberately salted by supernatural memes, and the mischievous efforts of Tormentor tourists have produced some remarkable results. A series of Torments inflicted on the Information Age Societum of Quiberon resulted in a robust transhuman group mind, the 'Enlightenment', which has now become a major player in the Crucis Corridor.
On the other hand many closed lo-tech worlds have been infiltrated at various times by Tormentors; these events invariably cause interstellar tension (like the unauthorised vampire attacks on Virtual Siam in Oikoumene Cybernode 12^4 + 32^3); and sometimes the tourists are relatively innocent pawns in an ongoing struggle between high toposophic entities. Such a struggle can be dimly glimpsed at best from a near-baseline perspective, but the effects are often profound and disturbing.