If someone is crossposting, how many posts do you report?

[Shell]

Not saying anyone here is crossposting. But if they do; do you report one post or all of them?

[Ad Bot]

[Dr.Block]

All but the first one, I guess.

[Mega-Bear]

Two or three I would assume, so that a sufficient amount of evidence is given. If all the crossposts are back-to-back then report just one because Badspot can look at post history and see all of them.

[DrenDran]

Either way, Badspot will see the reports and consider action accordingly.
Just report as much as you'd think he'd need to see, I suppose.
He's a human being, so I'm sure he can take context (e.g. look in other boards for the crossposting) into consideration.