Unless you have a truly exceptional amount of krausen, or are really overfilling the LBK, the blowouts are probably due to overtightening the lid.
Ease off, guys- that lid should just barely make contact. If you tighten it too much, you're closing off the vents, and building pressure. This could be dangerous since that container isn't designed to hold it.
Exploding plastic can fly at high speed, and even if you snort derisively at the idea that it's going to cause real harm, consider the much worse implication:
If your LBK blows up, you're going to waste beer!