Here (behind paywall). Excerpt:
In mid-November, a Twitter group called Sleeping Giants became the hub of the new movement. The Giants and their followers have communicated with more than 1,000 companies and nonprofit groups whose ads appeared on Breitbart, and about 400 of those organizations have promised to remove the site from future ad buys.
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[A] a new consumer movement is rising, and activists believe that where votes failed, wallets may prevail. This struggle is about much more than ads on Breitbart News — it’s about using corporations as shields to protect vulnerable people from bullying and hate crimes.