30sec cooldown for Flag Cap
30sec cooldown for Teleport Scroll
On top of that, each costs 250 gold. Now, even if both people did this, that would be two flags capped and held for 30sec after which your team can cap if they tried. Your team could harrass them off of a flag, or just cap the extra flag (there's always 3) and gang up 2vs1 on a single flag of theirs.
It's a great methode that can easily be rectified by doing the same yourself ang then ganging up against the enemy. My team did this after the enemy team started blocking off flags with caps. We won because we got the most kills both in creeps and players so our citadel quickly upgraded and our creeps pushed way back into their territory.
"Best defense is a good offense!"