Does WPMU have a strength of password plugin?

I noticed that the signup (regular wp-signup.php) for my multisite does not have a way to gauge the strength of the password that the user is typing in. Is there an easy way to add this feature to the registration process so that everyone who signs up for a site on my network must choose a strong password?

And, to follow up on that question, if someone does create a subsite on my multisite with a weak password and they get their site hacked, can that jeopardize my whole network?

Thanks, Joe.