420 is a bad number. I didn't think so until recently but like Joseph kony that's just because nobody really knew about its bastardry. Whilst a number of course cannot enslave invisible children (which I assume is to steal chocolate or something) it can cause conditions such as brain tumors, strange and erratic behaviour, mathematician's finger, and pooflonge.
The individual components of this number are not to be sniffed at either. 400 is the number of babies Stalin ate during his reign in search of a more potent moustache. Twenty is the true number of deadly sins (and includes acts such as sarcasm, farting, and being indecisive). Zero is of course nothing, the worst amount of anything that isn't country music. Put together they form a number worse than 666, 13, 911, or any other dickish number from history.
Have you seen this number around recently? Fortunately the date of this number passed us by some time ago, and we are relatively safe from it's baneful occurrence for another year or so. However, quite terrifyingly, the time known as 'twenty minutes past four', or 4:20 when more frivolously formatted, occurs twice in every day! If you ever notice this time happening stop it at once! Close your eyes and think of Moomins, chocolate cereals, and the theme tune to The Wombles. Anything to escape the dread of 4:20!
There are some people (and I'm not naming any names. You know who you are. Yes you!) who have sadly joined some sort of cult relating to the worship of this number, who's terrible presence is celebrated every twelve hours with the ritual smoking of drugs that not only impair the mind, but put evil little minions into their lungs who whisper 420 at passers by during casual conversations, causing much discomfort to say the least.
If you ever come across one of these cultists, consider them strange and dangerous, as the evil power of 420 grows as you approach it's magical minute. Consider dispatching them swiftly using a katana or sai, or better yet, some sort of incendiary device such as a tactical thermonuclear warhead. The threat they pose to the world's safety really can't be understated.
Unfortunately this is all I can say on the matter, as if I type 420 one more time I may just grow out my hair, sprout a crap beard, start talking slowly and somehow get the impression I know something you don't, right before I crush a bag of kittens. All because of the evil of 420.