That’s the article view that greeted me when I tried to read one of the news articles on the Android NDTV app. MTNL has been doing this for the last few weeks in Mumbai, and I’d noticed it earlier while browsing sites on my iPad, laptop and phones as well. I finally gave up and decided to block the IP serving these ads – 203.94.227.140 – at the router level itself so that I wouldn’t be bothered on any device.
In fact this doesn’t seem to be the first time MTNL has done this given Yogesh’s similar post from over a year ago which also contains instructions to block the ads in greater detail (maybe first time in Mumbai though). If you want detailed instructions, check out his post, and use the IP- 203.94.227.140, as his IP seems to be for MTNL Delhi. It is also possible that they start using other servers, so if you come across any MTNL ad, right click and check out the source server IP, and then add it to your router blocklist. In my case, I found the IP this way, and then enabled the firewall on my TP Link router and added a rule to block this IP (use add WAN host to add the IP).
If you check out the user posts on the MTNL Mumbai facebook page, you’ll find similar complains from other customers as well. Airtel drew its share of flak sometime ago for similar behaviour, but the MTNL shenanigans have gone almost unnoticed with hardly any mainstream coverage.
This is a very poor way to treat customers and it really gets in the way on mobile devices. Of course, this kind of injection only works on non secure sites only, so HTTPS sites like Google, facebook etc should be problem free. Here’s to hoping that MTNL stops being user hostile.
AB's Reflections 
Hey man, I’ve IP blocked 203.94.227.140 on my router too and that’s successfully stopped the popups, but now one in five-ten page loads stalls while the Chrome status bar says – “waiting for 203.94.227.140”. Then you have to cancel and reload the page. Not exactly a perfect fix 😦
I agree with you – somehow there just aren’t enough people or media raising hell over this issue. I wrote to the DG MTNL, but as expected there was no response.
Yup, I’ve observed pretty much the same behaviour on my end as well. Not much we can do I suppose.