Of course, what's not mentioned in the media is what conversation took place between LinkedIn and Twitter, particularly what conversation took place about money. LinkedIn may have been "cut off" in one sense, but in another, more grown-up sense, the two companies failed to negotiate an agreement for continuation of the traffic. This could just as easily have been LinkedIn saying "fuck you, we won't pay $X, we don't need you that badly" as it have could been Twitter taking its ball home. All we see from here is the relationship ending, and the post-hoc PR rationalizations that fact generates.
The only pattern seems to be that APIs will be free and easily available from startups, and the ones that succeed will later try to monetize that traffic the way they monetize their other traffic, and they'll do that not when their own business reaches a certain size, but when they have a large enough user of the secondary traffic that it becomes an issue for them.
No amount of "open source" ethos will change the fact that companies need to not have their business cannibalized by competitors. It might be fairer if startups declared that the APIs won't be free or unrestricted forever, but then a little common sense on behalf of API consumers would go a long way too. This should be documented in an industry standard? Really?
"If you're not paying then you're the product" is a paranoid declaration, but the grain of truth it contains should cause businesses to pause before rolling out products that rely heavily on other commercial entities with whom they have not even a Memorandum of Understanding. Frankly, such businesses shouldn't even get past the family-funded stage, and now Bubble 2.0 has burst they probably won't in future.