You are not modifying slack (their product), when you request a website all they are sending you its a bunch of characters, including characters inside CSS or JS files, rendering those its up to your machine, you are not legally binded to render those in a specific way, otherwise screen readers would all be completely illegal, all threads of not modifying your local render of a website always end poorly by the people doing such threats, examples:

https://www.reddit.com/r/IAmA/comments/2r3uok/we_developed_a...

https://www.quora.com/Is-AdBlock-legal-If-not-specifically-w...

> You are not modifying slack (their product)

Their product are the bits they ship to you and the code they run on their servers.

You're modifying a part of their product.

Since you can't modify their product, you also obviously shouldn't be able to use any web browser to view slack because those browsers take those bytes they ship you and interpret them in the context of the browser windowing system (its userChrome.css for example)... that's also clearly modifying the experience they delivered to you.

You also shouldn't be able to use a computer monitor that has color settings different from the web designers working at slack. If you accidentally have a monitor with slightly less blue than theirs, well, you just modified the slack UI to be a little less blue. Obviously a ToS violation and you shouldn't use them at all.

God forbid if you zoom in on the page to modify their product's resolution/size.

He he, too funny you mention zooming. I've had a bug report going for a while where their emoji sprite sheet gets all messed up if you run at smaller zoom levels. I think they still haven't fixed it properly. :)

Because people who zoom do not deserve to be on the internets.

I hope your eyesight stays 20/20 for the rest of your life.

Jerk.

He was being sarcastic... I think.

No you are modifying that rendered part. A website can't control what you do with the output.

>Blocking ads is not quite the same thing as modifying a product

Explain.

> Blocking ads is not quite the same thing as modifying a product

I was going to comment something similar, but in trying to come up with details and examples to explain my point, I realized I couldn't, I so I decided they aren't really different with respect to modifying a product. What makes them different is how the product was modified, but that presupposes modifying the product and that's not really the way the question has been posed.

Blocking ads is removing the revenue mechanism, and is akin to patching out account verification for a desktop product (assuming the webapp/webpage has some AUP stating that the ads are required to be viewed as part of the service).

Modifying a program takes many forms, from removing authentication mechanisms to fixing bugs or adding enhancements, so while the legal system may or may not acknowledge those differences, it's at best an overly broad description of the case in question.

They don't sue adblockers because they wouldn't win.