F R E E.
It's quite possibly the single word one sees the most on the internet.
Apparently, you can get free christmas gifts, weight-loss products and liposuction operations, pet medications, xbox-es, "I love NY" t-shirts, inkjet cartridges, cars, books about not paying taxes, drugs, broadband connections, credit card bonuses, painkillers, DVDs, magical sex-attracting lotions, memberships to "americansingles.com", business cards, lockpicking tools, anti-snoring patches, disney movies, cell phones, penis enlargement pills, dental care... (All of this, by the way, I just got from a quick look into my KMail "trash" folder).
You can even get free money, for Pete's sake! Somebody wants to send me a free one euro coin.
You'd think one could save a hell of a lot of money by just following the helpful advice of unwanted emails.
And if you've ever surfed for porn, you've probably seen the word "Free" so many times you now get apoplectic fits every time someone mentions it.
The truth is, there IS free stuff on the net.
There's free information. BBC, CNN, you name it... they all offer information on the net without charge. There's a large number of amateur sites about just about everything, from how to care for your cat to the implications of using rechargeable batteries in laser pointers (as you may or may not know, these two things are closely related), that don't charge you.
But this is only text, and the occasional image. The internet will not give you free material possessions. Nobody gives anything for nothing... Unless, of course, it can be duplicated without any loss whatsoever. Files can be duplicated, but you can't miraculously build a car out of thin air by just having the original nearby (I wouldn't be surprised if someone actually fell for that, though).
The exception is porn; as it's a very requested sort of "information", it falls under a separate category: not material possession, yet partially regarded as such.
The point of all this is: if someone tells you to register "for free", and then asks you your credit card number, you should become *very* suspicious.
Many websites tell you they need the cred card number to be assured that you're of legal age.
And if you believe that, you deserve to be robbed of your last cent.
Porn websites don't need to have your age certified; they can easily get away with legal responsibility with one of those don't-enter-if-not-above-18 disclaimers nobody ever reads anyway. They need your cred card number to extract money from your account.
When an e-mail tells you to order something "for free", and then asks you to submit all your personal data, you should also get *very* suspicious. Apart from the privacy issues of giving personal data to unknown people, you risk to either have to pay for some never-previously-mentioned service which is needed to get you your "free" goods (and then never receiving such goods), or to have the goods delivered with a humongous bill, and all your protests will be vanquished by a microscopic-characters-on-a-contract style explanation, like "only the order is free, you have to pay for the goods".
So please, please, please, don't fall for "free registration" scams. If they exist, it's because someone thinks you may fall for it, which means some people must have fallen for it before you. The less people do this, the less scams we'll (hopefully) see.