Sanket's right. While the bots that crawl our forums do us the favor of putting our sites in google searches so we can be found, there are also "spiders", which are bots too, but they have bad intentions.
They crawl looking to phish and steal things. One thing they do is
look for e-mail addresses posted visibly. Any they find, they can add to a spam list. Filters are fine, I guess (although once spam reaches a critical amount, you kind of just need to abandon the mail account), but you cant "filter" away spiders. They are just there. And because of that, I tell my members never post e-mail addresses in chat or posts (only in pm's is safe).
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Alright, to your original post: I have tried Yahoo, MSN, and Skype.
1- YAHOO: Awful! Prone to unending attacks, key-logging and viruses. I'll never use Yahoo again. They didn't even fix this problem in three years they've been receiving complaints about it. (It doesn't surprise me really. Have you ever been to Yahoo Answers? It's a beautiful idea, but they don't moderate it; they just leave report buttons, thinking it can be "absentee managed". Well people abuse the report buttons,so the site is chaotic and hemorrhaging members. And this is tragic; it's not the first time I've seen a site succeed beautifully, but then become awful or even die because the owner didn't care to ever pay any attention to running it.
But I'm not out to give Yahoo a black eye. Other things they offer are great, like their web-hosting service, and of course their search engine. I think it's worth it for them to fix a couple problems...
2-SKYPE: Is very good! If I couldn't get MSN, I'd use Skype. (It's only downfall is everyone isn't using it)(Well, you kind of need to have the same messenger your friends use, to be compatible).
3-MSN: This is what I use. Everybody does, and it's perfect. I cant think of a single complaint. It's safe. Reliable. You can add your own emoticons to it. All the features are there. It's great.
4-LOGITECH VIDEO HD: This one, and Skype, both offer the chance to multi-vid chat. (MSN could add that feature). They charge a fee for this, but if you really want to "be there" with your close buds from around the world (I'm in United States, and my friends are in Finland, Ukraine, Chile, England...)nothing beats having your screen show four video chat windows. it's beautiful. Well worth it. I think the Logitech Video HD service is slightly better than Skype is, because they let you pay for the service, but your friends don't have to (ie,for four friends to multi-video chat, only one has to be a paid subscriber to the service. The other three can just be "invitees" of the conversation).
I may add this soon, if my site grows at all, because i think it would be a great business tool, to be able to have business meetings, by video chat.
Oh but I do go on..
XD