in the US, one has so far flown under the political radar,

so to speak.

DJI makes 70 per cent of the drones sold across the US

every year.

And yet it has escaped the kinds of scrutiny

that have been imposed on other Chinese tech

companies such as Huawei.

One reason for that is the company's tech.

There simply isn't another maker on that scale

of commercial drones.

But another is that DJI is extraordinarily well plugged

in in US political circles.

Its executives sit on key regulatory bodies.

It has teams of experts ready to jump at a moment's notice

should anything go wrong with a drone owned by the government.

And it has even worked hand in hand

with a Department of the Interior

to develop a drone made specifically

for the US government.

Now all that might be changing.

I've had several conversations with people in the Trump

administration over the past few months

who have said that they are concerned

that the photographs taken by millions of DJI drones

across the country could provide a treasure trove of data

for the Chinese to use for spying, should they wish.

So far, nothing much has happened.

But the Department of the Interior

has grounded its entire fleet of drones,

including 121 made by DJI, while it investigates whether they

pose a security threat.

And senators are considering applying a complete ban

to federal government on buying the company's drones.

But so far, this is one big Chinese company

that can still get a hearing here in Washington.

Now each week I'm going to answer one reader question.

And this week, it comes from Stefan.

And it's on the subject of Twitter's recently announced

ban on political advertising.

Stefan asked, "How do you define political advertising compared

to ordinary advertising?

A Greenpeace, for example, is also political,

so should that be banned as well?"

Well, Stefan, this is one reason why Facebook has not

followed suit, at least so far.

It is very difficult to define the boundaries of what counts

as a political advert and what doesn't.

This is something that Elizabeth Warren is very concerned about,

for example.

She tweeted earlier this week that she

was worried that under this ban a company like Exxon

might be able to advertise about its oil business

but a group campaigning against climate change might not.

Now so far we don't know if that's going to be the case

or not.

Jack Dorsey, the Twitter CEO, has

said he will announce the full set of rules later this month.

But one thing is clear - whatever

he announces on the 15th of November,

someone is going to be very angry indeed.

Thanks very much for your question.

And if you have a comment or a question

you'd like me to answer in next week's vlog,

please leave it in the comments below.