I wouldn't go so far as calling Keybase or Stellar liars or shady. They covered themselves pretty thoroughly from the start. Here're sine excerpts from their announcement back in September:
Quote from: https://medium.com/stellar-development-foundation/the-2b-lumen-keybase-space-drop-2c1c00ef3ce0
Today we’re excited to announce we’ve partnered with Keybase for our largest airdrop ever.
They’re giving away up to 2B XLM over the next 20 months (100M XLM each month) to Keybase users. All you have to do is have an authenticated Keybase account, and your XLM will appear in your wallet — automatically, every month, for as long as the airdrop continues¹.
~
[1] The airdrop will run for at least 3 months, with subsequent months subject to basic success metrics for the program. To qualify, you must have a Keybase account registered before this announcement OR if you’re new to Keybase, you must connect your Keybase account to a GitHub or HackerNews account that was registered before this announcement. See Keybase’s announcement for more details.
They’re giving away up to 2B XLM over the next 20 months (100M XLM each month) to Keybase users. All you have to do is have an authenticated Keybase account, and your XLM will appear in your wallet — automatically, every month, for as long as the airdrop continues¹.
~
[1] The airdrop will run for at least 3 months, with subsequent months subject to basic success metrics for the program. To qualify, you must have a Keybase account registered before this announcement OR if you’re new to Keybase, you must connect your Keybase account to a GitHub or HackerNews account that was registered before this announcement. See Keybase’s announcement for more details.
As you can see the wording "up to 2B XLM," followed by the disclaimer. They weren't obligating themselves to running the airdrop for any more than three months, and once the this month's airdrops are complete, they will have honored their commitment.
None the less, it would be nice for them to do another airdrop with Keybase if they can figure out how to stop people from abusing multiple accounts.
