It’s hard to give the ‘right answer’ as to why people stalk other than “it’s crazy people”. Doesn’t matter whether it’s from RP or other subset of community. All it takes is just one person or group crazy & wanting enough to cause harm to their target that they dislike for whatever reason.

Google & take your time reading the “FFXIV Koike Incident” and “FFXIV Dingo Case”. While they’re not about stalking strictly, they’re certainly something that can happen more easily should more and more people, good or bad, becomes aware of the BL system flaw. Besides, oftentimes, ‘stalking’ doesn’t necessarily means ‘just following you around lol.’ They worsen the spaces you regularly go to and tend to affect those that normally hangs with you as well.