I think Twitter bought Periscope (In January Sometime) before Meerkat launched (Early March), but Twitter didn't disclose the acquisition until after Meerkat launched (Mid March).
I'm happy for them. Don't get me wrong, I love meerkat, it's a great app. Periscope looks like a one night hack for me. My point is that their entire app relies entirely on Twitter.
- v1 of Meerkat was posting on user's behalf without permission, auto-follow @Meerkat on sign-up, sending Twitter notifications without permission.
- user's social graph cannot be ported to the 3rd party apps
- recreating commenting network using Twitter's API
This is why I am not surprised Twitter blocked them. They say: "you don't shit, where you eat".