TikTok Killed the Vampires
Vampires could never feel really plausible, but Vampire: The Masquerade created a lot of fantastic reasons to buy into the World of Darkness. Enough that once the reader allows the vampires and their magical powers, the masquerade they all keep - the mass conspiracy that they don't exist - feels easy to swallow.
Pull yourself, dear reader, back to the 90's, where the only way to get on television was to apply to prove you could read pre-approved lines, and the only way to publish a letter to the country was to have a newspaper accept your message.
The vampires have blood-enchanted servants here and there, maybe editing a newspaper, perhaps running the presses and waiting for any last-minute alterations. Others might sit on a censorship board, reviewing massive amounts of plays and films, before anyone can see them.
And if something happens to slip through these many nets, a single report could never suffice. If a newspaper interviews a vampire, then publishes it, with a photograph of a Lasombra's shadow-play powers at work, any sane reader would immediately conclude it's a fake, or an April-fools run that went out early.
Perhaps the greatest danger to the masquerade, or at least the most difficult to clean up, arise from individuals spreading the word quietly. A few meetings with Marxists here (explaining the Burgoisie are in fact the undead), and a few late-night board meetings with investors (explaining why their primary clients never appear at meetings), and once can convince dozens of mortals about the presence of the undead. If one can keep this up for a few months, at each meeting displaying some supernatural power and explaining what to look out for, and where the local vampires meet and hunt, then hundreds of mortals could leave with a working knowledge of the Occult world.
If no records have been kept of which mortals know, then identifying and dealing with them could prove extremely tedious. Of course, each of them will have trouble relaying the information to others. And any attempt they might make to meet up, through advertising or simply shouting on the streets, opens the door for vampires to enter and deal with them.
Once found of course, anyone talking about vampires could immediately be reprogrammed with Dominate. The advantages of Dominate over simply killing them are clear - no corpse to clean up, no story about how they died, and nobody notices the mad guy at the meetings who says the investors drink the blood of children has disappeared one day. He simply 'changed his mind' and 'gave up on childish fantasies'.
This leaves a lot of the masquerade in the hands of the Ventrue and (until 1997) Malkavians, which fits rather well with the Ventrue image that they must steward the other kindred.
TikTok
All that ends with instant video-to-internet streaming. Every single blood-frenzy in a club instantly gets transmitted, fangs-and-all, to the entire world. Any set of three vampires who want to break the masquerade can agree to split up, make a spectacle of themselves in three separate locations, and each one release a video explaining the entire masquerade, while naming a few vampires with real-world identities.
Of course, at this stage we could always bring in some explanation, such as the Technocracy, who control the world's computers, but the world feels every different here. We can no longer ignore them as some separate splat-book, which doesn't feature in our campaign. Every public breach of the veil must involve first the smart-phones, and then the Technocratic wipe of said smartphones. The local Camarilla and the Technocrats all wish to deal with the problem, so now we have to ask if the Prince and sheriff are having meetings, being given 'breach quotas', and so on.
In a cyberpunk world, we can imagine vampires existing, but we cannot imagine elder vampires, who fear technology, just reminding everyone to be careful and super-secret all the time. If I run another Vampire campaign, I may set it in the 70's, 80's, or even later, but I'm going to stick to the original timeline for Gehenna - so in 2004, the end of the world comes, and nobody has to deal with Facebook.