It's says porn in the title, but there is frequent reference to blocking 'adult content'. In this regard 'adult content' can be a very wide net. Sometimes blocking things which are not 'adult content' at all...
The Guardian article contains quotes which[1][2] raise my suspicions about the validity of this issue. I'm not an expert, but surely for such a large amount of users (plus, what I'd imagine is an easily accessed guest WiFi) the amount of block access attempts isn't that high?
Aside from that, why should I care that someone looks at (shock! horror!) 'adult content' on their phone? I'm surprised that this puritan attitude to pornography still persists. I also thought we progressed beyond the whole sex lives of politicians nonsense too.
[1] "A parliamentary spokesman said of the figures: “All pornographic websites are blocked by parliament’s computer network. The vast majority of attempts to access them are not deliberate. The data shows requests to access websites, not visits to them."
[2] “There are 8,500 computers on the parliamentary network, which are used by MPs, peers, their staff and staff of both Houses. This data also covers personal devices used when logged on to parliament’s guest wifi.”