It's hardly surprising that ≈0.01% of the population of Barcelona are ready to do property damage. The only surprising thing is that they managed to all be at the same place at the same time. Identifying Tiktok as one link in their organizing process doesn't mean Tiktok is to blame, but it suggests that one way to prevent future occurrences could be e.g. to have a dedicated police unit monitoring social media content so they're not caught unawares.