How to get rid of Google penalty

How to get rid of Google penalty :
If you have a website and you are a webmaster my story will be so helpful to you .It is a real story happened between me and Google. I really like Google and I think it is the best web search engine at the time of my writing and the most popular .Who knows how the future will be.
My website was doing well and has a good rate of traffic until one day I got effort to exchange link between my site and other related site, well. I said that is looks nice specially that the other site is almost related and has more page than my site does.

After one week of link exchange, I noticed my traffic started to decrease to almost -30%. I understood that the reason was the link exchange, that it must be something against GOOGLE policy .So I removed it immediately and I waited .After almost 1 month over my traffic started to return back to normal one, here I said “Oh ,thanks GOD . Everything is fine now”.
Before I go further in my story I have to tell you a very important thing about my site, my site is just a forums .My forum were under spam eyes for a long time because it has good SEO and high SERP. Every day I got 30-40 registered users, most of them are inactive. Everyday there was a spam topics like “For sale NOKIA”, “For sale CVV”. Actually I don’t know where these topics come from (Do you know?) .Who are these users, are they a spam engines that do automatic posting and registration. I opened a forum for sales to drive this posting to it and everything was going fine and actually it was increasing my hit rate per day.
But one day, I was at a vacation and I was disconnected for about 2 days. And once I returned online I checked my Google analytical account and saw what surprised me .WOW, my traffic was doubled .I said yeah “BOOM”. Then I started thinking how this happened in two days. Later and due to my bad luck, I figured what actually happened .Someone of the spams posted a lot of topics to my forums .About 40 to 60 topics but “porn” topics. (Why they do this??) . Yeah, my site is related to programming and IT. Once I saw these topics I deleted them all.

As you can see in the screenshot

One day after, my traffic started to decrease so rapidly in one or two days to be 90% less. Can you imagine this? This was my first time to face such problem. I remained at GOOGLE index, but I have BAD SERP. For the keywords that I used to get 1 page first link, I become at page 14 and later page 20! But in the same time my pr (GOOGLE page rank) did’t change. After one week of this, I started searching to fix the problem.

First thing came to my mind is to check my webmaster tools and see if there is something wrong , I noticed that there many back links to my website related to sales and buy the in the Spam topics.
https://www.google.com/webmasters/tools/
Some ideas got to my mind that these links may vote badly for me at Google. But actually I can’t do a thing about it, they are on other websites. But the fact linking to your site from unrelated site does’t harm but it does’t vote for you.
I made two important things which are:
I discussed my problem at Google support forum.
http://www.google.com/support/forum/p/Webmasters?hl=en
Asking in these forums is really helpful, there are very good experts there, those can take a look at your website and give you the needed advices.
I got replies like:
Stop any linking exchange mechanism you use.
Remove any duplicate, spam content from your site.
I got a passive answers like, your site is just a forum, Google don’t rank forums at high SERP. (Just answers made me depressed - but don’t give up there many people they like only to say what they think)

Second I made about four Site reconsideration requests, because every time I do nothing happens and the problem remains exists so I retry again. Actually I was trying to remove anything that is may be against Google policy and send this request again.

Finally ,
After two months, of just waiting and removing any spam, or any linking exchange, and making a legal back links like linking from forums. My site returned to normal traffic. Well, I just waited! And avoid anything against Google webmaster guideline
http://www.google.com/support/webmaster ... swer=35769
Note that you can do link exchange but using the attribute :
rel=”nofollow” in <a> tag .Google is not against the linking exchange , but it is against linking exchange that try to fake the search results and increase the site popularity with unaccepted why .
My advices to you:
Don’t be involved in any linking mechanism, it really harms more than it worth. Focus on good content and unique one. Be patient be patient be patient. Follow Google webmaster guidelines .And remember Google do what it thinks make high quality search results. What happened to me, is due to my lake of experience. But during these two months I learned a lot of things, that I never known before. My experience increased a lot.
Use anti spam mods and filters. Like words filters and advanced CAPTCHA, avoid linking until number of allowed posts exceeded.

What is really bother me , that when Google say "You are bad" .Your site go away from visitors hands . And you lose your main traffic .

After you read my story . please share yours about Google penalties .

Thanks mate, for the amazingly good explanation...When I saw my rankings to drop down from to 3 to 43, I was really worried ...waited for a month thinking that it may be a Google dance...I never knew about the penalty in first place then I dug the topic to find that penalties really exist...and they are like 30, 50, 90 and so on!!! But still I had no clue about what I had done wrong! Then I realized that I had recently renewed my forum signature(130 posts) which eventually caused 130 backlinks at once!...however this can not be the only reason for penalty then I found that the same keyword is over stuffed in my content, which was clearly indicating that it was a deliberate attempt of manipulating SERPs...and I was punished for it!

How I recovered:
I rewrote the content with minimal keyword density
Instead used the different variations of that keyword
Removed signature links
Change the navigational link text on site (of the link going to that page)

I still had to wait for a couple months but now its all fine...may be I should have considered sending 'Reconsideration Request' to Google to get it done quickly but I was afraid for obvious reason ...any ways, its for sure that you can get rid of Google penalty...but prevention is better than cure, so I have compiled few common things to avoid Google penalty in the first place itself.

What really bothers me , that when Google say "You are bad" .Your site go away from visitors hands . And you lose your main traffic .

Very true indeed

Google analyitcal is really nice tool that helps to know many things. I was really not aware about the google penalty it was fantastic information that I had got. Good work msi, I think your all article were worth to read. Keep it up.