Collection #1 is a set of email addresses and passwords totalling 2,692,818,238 rows. It's made up of many different individual data breaches from literally thousands of different sources. (And yes, fellow techies, that's a sizeable amount more than a 32-bit integer can hold.)

I hate to be that guy [1], but no, that does fit in a 32-bit integer - as long as it's unsigned.

From the tweet, it seems like SQL Server puts the result of a COUNT into a signed 32-bit integer, which really surprises me.

[1] I lied, i love being that guy.