https://www.vice.com/en_us/article/4axzzd/twitters-latest-chaotic-move-will-kill-the-sites-best-bots-account-owners-say

On Wednesday, Twitter announced that starting on February 9th, it would no longer be supporting free Application Program Interface (API) access, which allows third-party developers and users to access the app’s data. This decision will have the most impact on bots and researchers, and the owners of popular bot accounts are already sounding the alarm that they'll have to shut down.

Currently, Twitter offers a free API package that allows users to send up to 250 requests per month and 100 tweets per request. The paid "premium" packages range from 500 to 10,000 requests and $149 to $2,499 per month, respectively. Twitter has not yet announced how much the new “paid basic tier” will be. But many bot accounts—not spammers, but popular entertainment-focused accounts that make automated tweets—are already saying their farewells to their followers.