A group of more than 200 employees at Google's parent company announced on Monday that they've signed union cards with the Communications Workers of America, forming the Alphabet Workers Union.

Why it matters: This is the largest and most high-profile unionization effort among tech workers to date. The tech industry has historically eschewed unions, unlike other sectors like the auto industry.

• Only a couple of small tech companies, like Kickstarter and Glitch, have recently unionized.

Details: The union would be open to all workers at Google and other Alphabet subsidiaries, regardless of their jobs. Some other small groups of Alphabet workers, like HCL contract workers in Pittsburgh and cafeteria workers in the Bay Area, have previously unionized.

• The workers are seeking to form a minority union, which means it won't seek formal recognition from the National Labor Relations Board, won't need to win a formal election and won't be able to negotiate a labor contract with Alphabet.
• This also means that contract workers can join the union despite not having the right to formally unionize under U.S. labor laws.

The big picture: Alphabet has faced growing employee discontent over company practices in the last few years.

• The company's handling of sexual harassment sparked a large walkout in 2018. It has also received pushback on plans to potentially roll out a search engine in China and its work with the U.S. government to provide artificial intelligence analysis of drone footage.
• The NLRB recently filed a complaint against Google, alleging the company illegally spied on workers who had organized protests and fired two of them in retaliation.

The other side:

Go deeper: Read the union organizer's op-ed in the New York Times

Editor's note: The story has been updated with a statement from Google.