First off, what about all the folks in Montana who already have TikTok?
Will Montana State Troopers be setting up roadblocks to check people's phones, then going house to house to do the same?
And when it comes to stuff like this, kids aren't stupid. If they can't gain access to a VPN providing an IP address outside Montana, they'll just message someone they know from out of state with something like "email me the .apk for Tiktok" or have someone put it up on some site outside Montana, preferably outside the US.
I'd also expect that numerous scam/malware/other evil sites will pop up offering "the TikTok app," which of course will either be the app laden with malware/backdoors/RATs, or just the latter claiming to be the app.
Nothing good will come of this.
That's not to say I'm a fan of TikTok. I'm not. But the whole premise of laws like this are that the evil Chinese government is going to steal your childrens' souls (okay not their souls, but lots of data and PII) to be used as a weapon to destroy our nation, one short video at a time.
But the truth is that all the spying scumbags^W^W Social media like Google, Facebook, Instagram, etc. are doing all of what TikTok is, and maybe even more.
This is performative jingoism masquerading as "safety." Want to stop this hoovering up of data? Pass national legislation blocking all these peeping Toms from collecting this information at all.
Who's running Montana, the Keystone Kops[0]?
Edit: fixed prose. Used the correct term for "social media".
[0] https://en.wikipedia.org/wiki/Keystone_Cops
Edit: Added link to explain who the "Keystone Kops" might be for those unaware of their (fictional) existence.