Why Moz OSE, Ahrefs, Majestic and so on, don't change their user agent while crawling?

[astronaute]

Some blackhat websites, PBNs and other "cheaters" are using various methods to effectively block third party backlink checker bots (OSE, Ahrefs, Majestic...) : robot.txt, IP and such.

A simple solution for those bots would be to mimic Google by using its user agent string for example.
Or if not legally permitted (which I doubt) use some kind of randomness in user agent strings, urls, and IPs in order to prevent blocking.

This should not be a big deal IMHO, am I missing something obvious ?

[George.Fanucci]

The reputation and integrity of the major players would be at stake here. If they changed their user agent identification (to spoof Googlebot or Bing or whatever) that could be detected, and they would be castigated. The crawler IP address and its user agent ID would be out of sync...

[astronaute]

What about using different user agents and IPs regurarly in order to avoid detection ?

Is there any acceptable other solution ?

[KeriMorgret]

I agree with George here -- we'd hear a huge outcry if we pretended to be Googlebot or a different bot. We'd also likely get blocked, as sometimes people only let in a certain few known bots/IPs to crawl their site. If we changed user agents and IPs regularly, it would not be cool or TAGFEE.

[astronaute]

Well, I think bot blocking is an obvious problem even now, and will be more important tomorrow with all private networks as you can imagine.

MOZ (and others) should find and implement the best possible solution, I see no problem with TAGFEE as soon as you are transparent with regards to the fact that your bots are undetectable.

I understand that what I'm proposing is maybe not best nor wanted solution, but the problem must be addressed or OSE will soon have no value at all

What do you propose ?

[Cyrus-Shepard]

The ethics of the Internet dictate that you

1. crawl politely,
2. obey robots.txt and
3. properly identify yourself

This isn't a new issue. Link networks and sites have blocked crawlers and manipulated Google for years. Fortuneatly, it's only a small fraction of the web. Also, it unlikely links from those networks have much value, so crawl priority would be super low anyway.

Actually, it could be viewed as beneficial when blackhat sites block OSE and aHrefs, because those sites often get penalized by Google, but 3rd party crawlers have no way to know this, so blocking effectively keeps them out of the indexes.