[tjader]

> We access your private content only when we [...] are required to by law.

[greyface-]

The ellipsis is doing a lot of work there. The full sentence is:

> We access your private content only when we have your permission or are required to by law.

They will claim that you gave them permission by acknowledging the TOS.

[tjader]

The two subclauses of "when we" are joined by an "or", so only one of them has to be true to fulfill the "when" condition.

[kovac]

I think what he is saying is that if they get the user to agree through TOS then they always have permission via the first subclause you omitted.