The addresses are generated ahead of time and placed into a huge database. Every new transaction that is broadcast is checked against the database, and if any v

The addresses are generated ahead of time and placed into a huge database. Every new transaction that is broadcast is checked against the database, and if any vulnerable outputs are created they are swept immediately. For example, watch either of these talks by Ryan Castellucci: https://www.youtube.com/watch?v=f2s3_UG9IPU https://www.youtube.com/watch?v=f2s3_UG9IPU https://www.youtube.com/watch?v=foil0hzl4Pg https://www.youtube.com/watch?v=foil0hzl4Pg