Just make the bond a % of the entity's revenue. Like that (apocryphal?) story about how Nokia CEO got speeding ticket of several million dollars in Finland, due to the ticket being a % of income.

Although I suppose a fixed % would limit how many claims you can file, which might be an issue for megacorporations who actually deal with lots of infringement -- although it would definitely reduce spurious claims.

Hmm, maybe coming up with a good law is actually hard.