Liberalism does not, cannot, consider the possibility that restrictions on certain human behavior might sometimes be appropriate.
Sure it does: whenever your freedoms and liberties lead you to do something which either damages another or their own freedoms and liberties and their exercise restrictions are not just considered but actively supported.
And for the piece de resistance:
It must also (and finally for now) be recognised that liberalism is, above all, an individualist ideology and individualism is ultimately opposed to collectivism**. This may seem like an obvious point, but it\’s one that seems to be increasingly forgotten by much of the intellectual Left these days. It matters because there is no way that society can be significantly changed in a positive direction as a result of policies designed by an individualist thought process (another basic and totally obvious point, I hope) and because collective rights are ultimately incompatible with an ideology that places the rights and the liberty of the individual before everything else.
Err, liberalism is bad because it allows people to think for themselves?