Target User Agents and Reduce Spam via robots.txt
Your website’s robots.txt file probably contains some rules that tell compliant search engines and other bots which pages they can visit, and which are not allowed, etc. In most of the robots.txt files that I’ve looked at, all of the Allow and Disallow rules are applied to all user agents. This is done with the wildcard operator, which is written as an asterisk *, like this: User-agent: * This site’s robots.txt file provides a typical example. All of the allow/disallow […] Continue reading »
WordPress Plugin: Blackhole for Bad Bots
Image Courtesy NASA/JPL-Caltech. Update: Pro version now available! Check out Blackhole Pro » Finally translated my Blackhole Spider Trap into a FREE WordPress plugin. It’s fun, fast, flexible, and works silently behind the scenes to protect your WordPress-powered site from malicious bots. Here are some of the features: Continue reading »
Yahoo! Slurp too Stupid to be a Robot
I really hate bad robots. When a web crawler, spider, bot — or whatever you want to call it — behaves in a way that is contrary to expected and/or accepted protocols, we say that the bot is acting suspiciously, behaving badly, or just acting stupid in general. Unfortunately, there are thousands — if not hundreds of thousands — of nefarious bots violating our sites every minute of the day. For the most part, there are effective methods available enabling […] Continue reading »
Yahoo! Lies about Obeying Robots.txt Directives
There are two possibilities here: Yahoo!’s Slurp crawler is broken or Yahoo! lies about obeying Robots directives. Either case isn’t good. Slurp just can’t seem to keep its nose out of my private business. And, as I’ve discussed before, this happens all the time. Here are the two most recent offenses, as recorded in the log file for my blackhole spider trap: Continue reading »
Blacklist Candidate 2008-10-19
Welcome to the Perishable Press “Blacklist Candidate” series. In this post, we continue our new tradition of exposing, humiliating and banishing spammers, crackers and other worthless scumbags.. From time to time on the show, a contestant places a bid that is so absurd and so asinine that you literally laugh out loud, point at the monitor, and openly ridicule the pathetic loser. On such occasions, even the host of the show will laugh and mock the idiocy. Of course, this […] Continue reading »
Yahoo! Once Again Caught Disobeying Robots.txt Rules
Hmmm.. Let’s see here. Google can do it. MSN/Live can do it. Even Ask can do it. So why oh why can’t Yahoo’s grubby Slurp crawler manage to adhere to robots.txt crawl directives? Just when I thought Yahoo! finally figured it out, I discover more Slurp tracks in my Blackhole trap for bad spiders: Continue reading »
Unexplained Crawl Behavior Involving Tagged Query Strings
I need your help! I am losing my mind trying to solve another baffling mystery. For the past three or four months, I have been recording many 404 Errors generated from msnbot, Yahoo-Slurp, and other spider crawls. These errors result from invalid requests for URLs containing query strings such as the following: https://example.com/press/page/2/?tag=spam https://example.com/press/page/3/?tag=code https://example.com/press/page/2/?tag=email https://example.com/press/page/2/?tag=xhtml https://example.com/press/page/4/?tag=notes https://example.com/press/page/2/?tag=flash https://example.com/press/page/2/?tag=links https://example.com/press/page/3/?tag=theme https://example.com/press/page/2/?tag=press Note: For these example URLs, I replaced my domain, perishablepress.com with the generic example.com. Turns out that listing the plain-text […] Continue reading »
Taking Advantage of the X-Robots Tag
Controlling the spidering, indexing and caching of your (X)HTML-based web pages is possible with meta robots directives such as these: <meta name="googlebot" content="index,archive,follow,noodp"/> <meta name="robots" content="all,index,follow"/> <meta name="msnbot" content="all,index,follow"/> I use these directives here at Perishable Press and they continue to serve me well for controlling how the “big bots”1 crawl and represent my (X)HTML-based content in search results. For other, non-(X)HTML types of content, however, using meta robots directives to control indexing and caching is not an option. An […] Continue reading »
Yahoo! Slurp in My Blackhole (Yet Again)
Yup, ‘ol Slurp is at it again, flagrantly disobeying specific robots.txt rules forbidding access to my bad-bot trap, lovingly dubbed the “blackhole.” As many readers know, this is not the first time Yahoo has been caught behaving badly. This time, Yahoo was caught trespassing five different times via three different IPs over the course of four different days. Here is the data recorded in my site’s blackhole log (I know, that sounds terrible): Continue reading »
How to Add Meta Noindex to Your Feeds
Want to make sure that your feeds are not indexed by Google and other compliant search engines? Add the following code to the channel element of your XML-based (RSS, etc.) feeds: <xhtml:meta xmlns:xhtml="http://www.w3.org/1999/xhtml" name="robots" content="noindex"></xhtml:meta> Here is an example of how I use this tag for Perishable Press feeds (vertical spacing added for emphasis): Continue reading »
Yahoo! in my Blackhole
Okay, I realize that the title sounds a bit odd, but nowhere near as odd as my recent discovery of Slurp ignoring explicit robots.txt rules and digging around in my highly specialized bot trap, which I have lovingly dubbed “the blackhole”. What is up with that, Yahoo!? — does your Slurp spider obey robots.txt directives or not? I have never seen Google crawling around that side of town, neither has MSN nor even Ask ventured into the forbidden realms. Has […] Continue reading »
How to Verify the Four Major Search Engines
Keeping track of your access and error logs is a critical component of any serious security strategy. Many times, you will see a recorded entry that looks legitimate, such that it may easily be dismissed as genuine Google fare, only to discover upon closer investigation a fraudulent agent. There are many such cloaked or disguised agents crawling around these days, mimicking various search engines to hide beneath the radar. So it’s always a good idea to implement a procedure for […] Continue reading »
Suspicious Behavior from Yahoo! Slurp Crawler
Most of the time, when I catch scumbags attempting to spam, scrape, leech, or otherwise hack my site, I stitch up a new voodoo doll and let the cursing begin. No, seriously, I just blacklist the idiots. I don’t need their traffic, and so I don’t even blink while slamming the doors in their faces. Of course, this policy presents a bit of a dilemma when the culprit is one of the four major search engines. Slamming the door on […] Continue reading »
Invite Only: Traffic Control via Whitelist
Web developers trying to control comment-spam, bandwidth-theft, and content-scraping must choose between two fundamentally different approaches: selectively deny target offenders (the “blacklist” method) or selectively allow desirable agents (the “opt-in”, or “whitelist” method). Currently popular according to various online forums and discussion boards is the blacklist method. The blacklist method requires the webmaster to create and maintain a working list of undesirable agents, usually blocking their access via htaccess or php. The downside of blacklisting is that it requires considerable […] Continue reading »
Robots Notes Plus
About the Robots Exclusion Standard: The robots exclusion standard or robots.txt protocol is a convention to prevent cooperating web spiders and other web robots from accessing all or part of a website. The information specifying the parts that should not be accessed is specified in a file called robots.txt in the top-level directory of the website. Notes on the robots.txt Rules: Rules of specificity apply, not inheritance. Always include a blank line between rules. Note also that not all robots […] Continue reading »
