This time last year Twitter refused to pay rent for their HQ to get leverage to renegotiate - this only pissed their landlords so much that Twitter were served an eviction notice.
Now it seems that there might be a similar reason why Twitter has been restricting page views (and who knows, maybe even the API pull) - they've been refusing to pay for their cloud bills for the last few weeks.
The deadline for the payment being the end of June.