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.

Or foreign influence campaigns target legitimate greviances but attempt to expand the grievance beyond all proportion, reframe the concerns from solveable to evil vs good and attempt to purposefully inflame emotions rather than solve problems in order to weaken unity and ability of rival states to act against the agitating nation.