I think the answer comes down to how well you trust your developers to use the feature responsibly? Data from a external URL should be treated like any other untrusted input and as long as that is understood, what's the big deal?
The way I see it is that if you treat your developers like children and never let them handle sharp things, then you'll have developers who never learn the responsibility of writing secure code.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…