Of course it is. If pressed, they will surely find a justification for it in reducing spam and bots. Less defensible is why they would wait to get a phone numbe

Of course it is. If pressed, they will surely find a justification for it in reducing spam and bots. Less defensible is why they would wait to get a phone number until after you make an account. And of course, try not to compare it with the Chinese rules requiring phone number verification for online accounts...