Every day, the frustrations of New York City subway riders spew out in the form of 2,500 often profanity-laced tweets directed at the Metropolitan Transportation Authority.

“Thanks @MTA for making sure we can’t buy metrocards AGAIN,” wrote @itzMzLori, 31-year-old beauty blogger Lori Tenn, who found her card machine closed. “I swear I f—ing hate y’all.”

The...