It is trivial to buy 1000's of phone numbers with SMS all available through APIs. You don't even need to keep them. The grey web is filled with many of these services.
If I looked hard enough I could probably buy 10000 verified twitter accounts with API access right now, aged 1 year or older.
Yup. PVAs can be had for a couple of $, with the price going up if they're 'warmed' (with a history of innocuous activity, usually liking celebrity tweets, retweeting the occasional breaking news story or heartwarming puppy video etc).
If I looked hard enough I could probably buy 10000 verified twitter accounts with API access right now, aged 1 year or older.