[eluser]megabyte[/eluser]
Here's a scenario:
So you've built an online store, and you want to allow users to register anytime they want, as well as register upon checking out.
You decide to allow this without activation so that the user doesn't have to go check their email when they are making a purchase. The reason....to keep the checkout process as short as possible.
You use email addresses for account management, and think to yourself what if someone for fun starts registering 100's of email accounts. You could stop this by only allowing a user to register once per day from the same ip addresses, or you could set the account as actived once they login for the first time, then delete accounts older than a week if they have never logged in.
My question I guess, is not having account activation have the ability to easily ruin an account system?