Twitter launched its 6 second video app Vine on Thursday, and by Friday Facebook had already shown where it stands on the subject.
Reports arrived at the end of the week that Facebook had blocked users from accessing their friends lists through Vine.
When it launched on Thursday, Vine featured a "find people" button meant to search through a user's Facebook friends.
But Facebook reportedly blocked the feature, and now it results in an error message that says Vine is not authorized to access Facebook.
The rivalry between Facebook and Twitter heated up over the last year, and now it seems the two are determined not to get along.
Of course, if most users got their way, both social networks would coexist - at least that's how it seems, given how many of our Facebook friends have linked their Twitter accounts to publish tweets as Facebook status updates. That little blue bird is all over the news feed.
Then again, when have social networking companies ever put the interests of users ahead of their own?
Facebook's apparent hostility toward Twitter is nothing new; in December Instagram, recently acquired by Facebook, nerfed Twitter integration in a move that could only be interpreted as an act of social warfare.
TechRadar asked Facebook determine for certain whether the company is intentionally blocking Vine users and whether that could change in the future. The company has not yet responded, however.
Facebook Director of Platform Partnerships and Operations Justin Osofsky did post an update to Facebook's developer blog on Friday writing, "For the vast majority of developers building social apps and games, keep doing what you're doing."
But "for a much smaller number of apps that are using Facebook to either replicate our functionality or bootstrap their growth in a way that creates little value for people on Facebook, such as not providing users an easy way to share back to Facebook, we've had policies against this that we are further clarifying today."
He linked to Facebook's platform policies and referred readers to section I.10, titled "Reciprocity and Replicating core functionality."
Of course, all of Facebook's posturing could be just a cover-up for not wanting to play nice with the competition, but ultimately it's difficult to say for sure.