To count the number of posts that specifically sought to delegitimize the election results, we examined 18.7 million posts from Election Day through Jan. 6 within the likely U.S. political Facebook groups. We separated out posts from groups with “Stop the Steal” in their name and calculated which keywords and phrases were disproportionately common in posts from those groups using a text-analysis technique called TF-IDF. Then, we handpicked the terms and keywords that were meaningfully linked to election delegitimization theories (e.g., “stop the steal,” “steal the election,” “every legal vote”). We had about 60 terms that indicated delegitimization on their own, plus 86 more in two buckets that, if terms from both buckets were present, indicated delegitimization (e.g., a reference to absentee ballots on its own did not indicate delegitimization, but a reference to “absentee ballots” and “fraud” did.) We identified about 1.03 million posts that likely referenced delegitimization. Finally, we hand-checked a sample of these posts to estimate the proportion that actually sought to delegitimize the election, and got a precision rate of about 64 percent. (False positives included mainstream news articles, debunks of fraud claims, and references to other countries’ elections.) We arrived at our final estimate of delegitimizing posts by multiplying the two together, to get an estimate of a bit more than 655,000.