Why is Mumsnet insisting that I log in?

[CrispEater]

I spend quite a lot of time browsing Mumsnet on my Samsung tablet, not logged in. I rarely post anything but if I do, I do that on my PC because I can type quicker on a proper keyboard.
Just now I was in Mumsnet on the tablet and kept getting a pop-up that insists I should either log in or join. As far as I can see, there is no way of getting rid of this pop-up except by logging in or joining or giving up on Mumsnet. It looks very genuine to me.
I really can't be bothered to keep logging in when I only want to browse and I hate being forced into doing something I'd rather not do.
Is there some reason why Mumsnet now wants everyone logged in all the time? Or have I missed something?

I kerp getting an annoying block up fpr last few days from
The mumsnet site on my phone
No it's not my phone, it can't get a virus.
So cheers mnset!

No one would expect a forced login/signup in the form of a lghtbox, unless it's part of a paywall like The Times. From the user point of view it breaks convention ... and from the Mumsnet point of view it breaks trust.

This ^^