I suppose it depends dude, I mean under their licence agreement they can do anything they like from what I gather. I guess maybe in Weclock's case, something else got their goat about his account, but I hope its just a mistake.
EDIT:
Well, I suppose, but wegame is legit, not like sellers on ebay (most of the time)

I know soooo much about wegame that would frighten you.

Admit it: WeGame is actually a cover operation run by North Koreans.

until I found out for what, I can't say.

Question: How is someone supposed to know you've been given a game fraudulently? Accepting games from people you don't know or trust pretty much fits everyone. All we know about each other here for example, is what we post. There is no way of really KNOWING anyone.
If Steam made the mistake and they have the technology to correct it, then by all means, they should simply delete the fraudulent games from the accounts and refund the money to the buyers, since even the buyers don't have any means to really tell the super duper offer they're seeing on the Steam store is a mistake.
I'm hoping it's just a mistake. I'm really not liking this "we can do whatever we want with what you buy after you've bought it" thing.

Maybe its a blessing they still haven't sent me garrys mod. I hope you get your account back though, I know you have a ton of games on it.

To be fair, every DD service has this policy.

Indeed.
It really, really sucks that it happened to you. Hopefully they'll get it all sorted out and you can go back to playing TF2. I love that game.

Well, Gamersgate doesn't have a software client you have to use, so you don't have to install anything extra. Your games are on an account and you download them when you want. You use a one time downloader/installer...but backing up everything (including the setup files) is very, very easy to do. I've got all of my GG buys backed up on my external drive along with my GoG installers.

Yeah, that's the one i meant, thanks for the link.
A mod on the boards seems to have fed him the bs about stolen CC numbers, but it appears that what actually happened was that the system looking for accounts used for pishing screwed up and mistakenly tagged his account, judging by the message he got from 'Miles' when his account got re-enabled.
So basically it's the same situation, an user account disabled without the user knowing why untill Valve either re-enables the account or confirms the account is perma disabled and explains why.
As for gifts,
"There is a Zero-Tolerance policy for any violations of the Steam Subscriber Agreement and Online Code of Conduct. All accounts in a user's possession for any of the following activities will be permanently disabled:
Redeeming Fraudulent Gifts
Never accept a gift from an unknown user. Any accounts tied to a redeemed gift from a fraudulent source will be permanently disabled.",
So basically i think you're right, it's a big effing risk to accept any gift. Even honest people that you know and trust are prone to having financial and bank problems/errors at any time and if there's a mix up or an error or something, there you go hat in hand begging for your games back.
That's what people get with the wonderful "you have nothing but a subscription" system. The hammer doesn't fall on the 'questionable' one item in question, it slams hard on evertything tied to that subscription.

I'm definitely done buying steam or valve games as a result of this, I can't stand this feeling, and I don't want anyone else to have a feeling like this either.

That's exactly what I ended up reading, good information matey, I should have posted that really.
I hope you get your account back at the very least Weclock; I know the feeling. In the meantime, keep us updated with any information support send you.

they disabled my account at roughly 10:00pm Phoenix time, which I hastily sent them an email (first thing I did!), and since then, I have received no replies.

A reply from Steam support takes at least 3-4 business days. I have never heard of it being done quicker,except in the case of stolen accounts, which they give priority to.
You know yours was deactivated though, not stolen, correct?
It sounds like you accept a lot of gifts and maybe use poduct key stores, so this might very well be related to that. I can't really speak with authority on the issue because I always buy from official vendors, that's just my personal philosophy about supporting publishers and developers.
Steam having total control of my ability to play my games does scare the heck out of me... I mainly use it for download-only titles, stuff like Crayon Physics. I prefer a box anyway, most of the time, being somewhat a collector.
Still, they have deals you often just can's pass up, like the current Red Faction 3 deal where you get both older games for free. I have to try really hard not to bite on stuff like that.