GPLv2 requires you to either distribute the source with the binaries, or provide the recipient information on how to obtain the source code. It also states that providing a link to the source code next to the binary download on your website is sufficient. See GPLv2 section 3 for more details.

TikTok have not provided a link to its source code, not are there instructions on their site or within the download package indicating where users can obtain the source code. Therefore, it's a violation.

The binaries must be accompanied with an offer of the source code. There is no mention of source code anywhere during the download, install or execution of TikTok Studio, nor any offer inside the application folder or similar.

That makes sense, they need to let people know how to obtain the source code.

It is not within the limits of GPLv2. If you go the "written offer" route, you have to actually make the offer, and it must be valid to anyone for 3 years.

Tiktok has not done that.

You also can't do it post-facto :)

Sure but then couldn't whoever receives the USB or DVD post the source code someplace more convenient? I'm not sure what that "workaround" would accomplish.

It's much worse for them actually. They're obliged to offer this for no more than the cost, unlike a typical "cost plus" basis on which they could profit even minimally - and yet they're also obliged to fulfill all orders from anybody. The offer isn't valid only for whoever you gave binaries to, it's an offer to any third party that's what the requirement says.

In the CD era, it might have made sense to go with written offer if the source is far larger than the binary you ship (e.g you ship a 500MB game on CD, but the source would be 1400MB so that's like 3 CDs, ugh) and you're happy to periodically pay the office intern to burn some source CDs and post them off for the inquisitive customer who asked for them.

In the Internet era it definitely doesn't make sense. Just pop a link to the source next to the binaries and don't sweat it.

Unless, of course, you have no intention of complying anyway.

It's designed to discourage people from exercising their GPL rights. If they push code every day and the only way to get the most updated code is to pay for a CD to be mailed to you, it becomes quite tiring to keep an up to date online copy.

Yep. "available on request" is perfectly allowed, there's no requirement that it be on a publicly available webpage.

This is totally wrong. It must be an explicit offer for source.

" 3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: ...

b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, "

Note accompany it.

The only exception is this: "If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. "

No, the offer of source code must be explicit, not just available if anyone happens to ask.

The offer yes, but the code does not need to be that easy to publicly access. Of course once the first person to request the source via that offer gets it (assuming they come good in that respect) it might be made more easily available.

Sure, but did anyone installing the TikTok streaming software get such an explicit offer? If not, then, hey, GPL violation.