They should not. Ever.
Why? For several reasons:
1. Filtering is error-prone.. it will end up blocking or letting through information that it shouldn’t – and the fixes might create more problems than they solve.
2. Filtering with ease opens up the door for abuses. Carriers will be tempted and succumb to temptation to filter what they’re not supposed to. That can ruin fair competition, people’s lives, and even Democratic process and Freedom.
3. Policing should never be given to a for-profit entity with no civic transparency. If we can’t obtain their records, control their funding, or vote them in and out of “office”, they certainly should NOT be in charge of policing. Judicial corruption is bad enough already, we don’t need net-cops “maximizing profit” at our expense.
4. AT&T is already guilty of enabling the illegal NSA spying on Americans.. these are federal crimes.. Treason crimes! There is NO WAY we can trust people like this with positions of legal authority.