It is the biggest problem I have ever faced as a webmaster. It threatens the existence of the site if left unchecked.
The more advanced tech people understand some of the tech issues involved here, but given the nature of the current feedback, there needs to be a better explanation of the severity of the problem. So lets start with a review of the situation and steps we have taken that lead us to the required login action.
It is not a question of how fast the site rippers pull pages, but rater the totality of all all of them combined. About 75 bots hit us for almost 12 million page views two weeks ago from about 300 ip's (most were proxy servers). It took the better part of an entire day to track down all the IPs and get them banned. I am sure the majority of them will be back to abuse the system. This has been a regular occurrence that has been growing every month we have been here. They were so easy to spot in the beginning, but it has grown and grown until I can't do anything about it. I have asked and asked the engines about the problem - looking for a tech solution, but up until this week, not a one would even acknowledge the problem to us.
The action here was not the banning bots - that was a outgrowth of the required login step. By requiring login, we require cookies. That alone will stop about 95% of the bots. The other 5% are the hard core bots that will manually login and then cut-n-paste the cookie over to the bot, or hand walk the bot through the login page.
How big of an issue was it on an ip level? 4000 ips banned in the htaccess since june when I cleared it out. If unchecked, I'd guess we would be somewhere around 10-20 million page views a day from the bots. I was spending 5-8 hrs a week (about an hour a day) fighting them.
We have been doing everything you can think of from a tech standpoint. This is a part of that ongoing process. We have pushed the limits of page delivery, banning, ip based, agent based, and down right agent cloaking a good portion of the site to avoid the rogue bots. Now that we have taken this action, the total amount of work, effort, and code that has gone into this problem is amazing.
Even after doing all this, there are still a dozen or more bots going at the forums. The only thing that has slowed them down is moving back to session ids and random page urls (eg: we have made the site uncrawlable again). One of the worst offenders were the monitoring services. I have atleast 100 of those ips are still banned today. All they do is try to crawl your entire site to look for tradedmarked keywords for their clients.
> how fast we fell out of the index.
Google yes - I was taken aback by that. I totally overlooked the automatic url removal system. *kick can - shrug - drat* can't think of everything. Not the first mistake we've made - won't be the last.
It has been over 180 days since we blocked GigaBlast, 120 days since we blocked Jeeves, over 90 days since we blocked MSN, and almost 60 days since we blocked Slurp. As of last Tuesday we were still listed in all but Teoma. MSN was fairly quick, but still listed the urls without a snippet.
The spidering is controllable by crawl-delay, but I will not use nonstandard robots.txt syntax - it defeats the purpose and make a mockery of the robots.txt standard. If we start down that road, then we are accepting that problem as real. The engines should be held accountable for changing a perfectly good and accepted internet standard. If they want to change it in whole, then lets get together and rewrite the thing with all parties invovled - not just those little bits that suit the engines purposes. Without webmaster voices in the process, playing with the robots.txt stanards is as unethical as Netscape and Microsoft playing fast and loose with HTML standards.
Steps we have taken:
An intelligent combo of all of the above is where we are at right now today.
The biggest issue is that I couldn't take any of the above steps and require login for users without blocking the big se crawlers too. I don't believe the engines would have allowed us to cloak the site entirely - I wouldn't bother even asking if we could or tempting fate. We have cloaked a lot of stuff around here from various bots - our own site search engine bot - etc. - it is so hard to keep it all managed right. It is really frustrating that we have to take care of all this *&*$% for just the bots.
That is the main point I wanted you to know - this wasn't some strange action at banning search engines. Trust me, no one is more upset about that part than I am - I adore se traffic. This is about saving a community site for the people - not the bots. I don't know how long we will leave things like this. Obviously, the shorter the better.
The heart of the problem? WebmasterWorld is to easy to crawl. If you move to a htaccess mod rewrite setup, that hides your cgi parameters into static content - you will see a big increase in spidering that will grow continually. 10 fold the number of off-the-shelf site rippers support static urls than support cgi based urls.
Rogue Bot Resources: