Preservation of anonymity when using the Internet in the Moscow Metro

Some time thinking about whether to publish or not, but still decided to try to lay out my thoughts and ideas.
I'll tell you a little about the access points of MosMetro_Free, namely, how to remain anonymous and not provide your mobile number.

1. A bit of theory

When a person authenticates in the metro when joining the MosMetr_Free access point, an activation code and an activation link come to the specified number:

cdn.vmet.ro/auth/activate.html?code=98765&phone=79250251234&idmac=123456

where
code - device activation code;
phone - mobile phone number;
idmac is a unique database entry associated with the MAC address of the device.

You can follow this link and activate it from anywhere, just by being in the subway. This makes me happy.

2. The very essence

From item 1. it follows that if you specify a mobile phone number of your neighbor by country house, then in the provider’s database there will be a record that the device’s MAC will correspond to the neighbor’s mobile number.
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You can spare a neighbor and specify the number of the bot, who will wait for the SMS with a link - and he will go over it.
I decided to try and wrote a small bot, living by number +79854764956 +79684350383 . As soon as the SMS is received for identification, within 5-7 seconds it is already possible to use the Internet in the metro via MosMetro_Free

3. Ending

_{Thought to write more, but just wanted to share}

I will be glad to any comments, criticism and suggestions.

Thanks for attention.

UPD1: Replaced the bot's phone number with a new one. Slightly disappointing, but it was somewhat expected to get a limit on the number of devices that can be tied to one mobile number.
This is clearly not the end, we'll think of something else.