This is a hook for a modern or future sci-fi game.
The Internet has gone missing! No matter how characters connect to the Internet (dial-up, wifi, DSL, cable modem, ISDN, radio packet, satellite, etc.) they just can’t find anything on the Internet (or Ultranet or Crystal Wind* or whatever you call it in your world). They can connect and everything appears to be functioning, but there is simply no data out there. After talking with other people (in person, no less, since their online connections are down,) the group discovers it is just they that are having issues. Everyone else in the world hasn’t noticed a thing.
Who has sabotaged the PCs? For that matter, the PCs with neural implants (or some other form of cybernetics) how was it accomplished without their noticing?
* It’s my little homage to Daniel Keys Moran here. He calls the global network The Crystal Wind in his series of books.