It's on.

Tonight is the annual Great Valentine's Day Pillow Fight. Going down at Justin Herman Plaza at 6pm sharp, simply grab a soft pillow and start clobbering strangers until feathers and fluff fill the air. The only rule is no hitting anyone unless they have a pillow. OK? OK.

Also, event organizers have asked participants to "only use pillows with natural material like down or cotton so that any debris will not harm the bay or wildlife." And if you have an extra pillow you no longer want? Bring it with you for anyone in need of a weapon.

Follow the jump to check out more footage of past pillow warfare.