Comment by za_creature

> User agent strings are a sad consequence of websites incorrectly parsing them to enable functionality, resulting in a "every bug becomes a contract" type of situation.

Which is precisely why trying to legislate them is folly. Obviously the reason Android calls itself "Mobile Safari" is so that servers send it the mobile version of the site instead of the desktop one etc.

Which makes "accurate" an unreasonable requirement, since there is already a preexisting non-waivable requirement for inaccurate. When someone is making their "turn a web page into a PDF so you can view it later on the plane" software or whatever, it has to use a user agent string that will cause the site to send the version you need turned into the PDF.

> That being said, if you include GOOGLEBOT in your 1k long query string, alongside a very long page describing your crawlers, how to identify them, how to block them and how to set limits, no judge will find you guilty of concealing your purpose.

First, you're assuming that the person being prosecuted is the entities who are the nominal targets of the bill, when the real problem is when they're not. Because you're proposing a law that says anybody with an inaccurate user agent string is in violation, meanwhile everybody has an inaccurate user agent string.

Moreover, consider what you expect the outcome of legislating something like this is going to be. Sites could then try to either blacklist or whitelist user agents.

If they do the first one, that doesn't work, because the scraping service can change it whenever they want.

If they do the second one, that doesn't work, because now every third party has to start pretending to be a common browser even when they're doing something totally innocent or they get blocked by default for being something else. Which makes the user agent string even less useful than it is now, and subjects innocent parties to arbitrary liability for doing something they have to do or their client is broken.

> As for why the law is written as is instead of banning more specific functionality, it's so assholes don't get any ideas on how to bypass it.

You're describing autocracy. The way you make it so that you always prosecute someone is to make it so that you can always prosecute anyone, which is very bad.

I don't think anybody does a decent ua check, webdevs test only in their favorite browser, i.e. Chrome, so only Chrome is allowed. Is it intended? The very purpose of webcompat is to masquerade as Chrome.

How do you even implement an ua check? How many browsers do you know? How many browsers you don't know? How do you implement an ua check for a browser that will appear tomorrow?

I wrote my own http downloader. Do you know about its existence? How do you implement an ua check for it? Can I call it "wget" to make ua check easier for you? Can I call it "Mozilla/5.0" so that it's compatible with your ua check so that you don't need to change anything?

> User agent strings are a sad consequence of websites incorrectly parsing them to enable functionality, resulting in a "every bug becomes a contract" type of situation.

It's a bit old but https://webaim.org/blog/user-agent-string-history/ is always a good parable.