Manchester Arena incident. Might be useful to warn people not in the building to keep away. London Underground - similar case, warn people to not enter the station.

Problem is that:

a) it could lead to a stamped in venues - far worse than using a 'cryptic' message via speakers in the venue to get people to leave (which often works well in stations to avoid panic, including the 'Inspector Sands' announcements;

b) it could cause other terrorists who have yet to carry out their attack to bring forward their timing, possibly killing more people before the police can take action to arrest / kill them and/or quietly evacuate people where possible.

Most, if not all LU stations already have emergency warning systems at the station entrance and gates/staff to stop people coming in.

Often in emerging circumstances, the wrong decision may be made to contact people or give incorrect /contradictory information.

Abroad, such systems are used where large populated areas or the nation suffers from frequent very serious natural events such as tidal waves, cyclones/hurricanes, volcanic eruptions or more recently, tornados. Not exactly frequent in the UK.

Abroad, such systems are used where large populated areas or the nation suffers from frequent very serious natural events such as tidal waves, cyclones/hurricanes, volcanic eruptions or more recently, tornados. Not exactly frequent in the UK.

The Netherlands has a system as well - hardly the largest place or one that has common natural disasters. One use that I have heard discussed was a fire at a cheical factory with people being advised to avoid the area and stay inside.

I see it as a useful tool to have - as long as it is used responsibly and not over used, although I don't see that happening as if it's overused then people will ignore the alerts which defeats the point of having it.

To be fair, The Netherlands has a good deal of its major populated areas below sea level, and thus is susceptible to flooding in some extreme circumstances, rather like New Orleans in the US but likely far better prepared.

The problem is that 'being responsible' hasn't exactly been worldwide politicians' / governments' forte of late, has it? Especially when conveniently a certain legally-binding WHO treaty is up for adoption that would seemingly use such a system for far more than most people (MPs seemingly included) either realise or are willing to admit.

You will not receive alerts if your device is:

• turned off or in airplane mode
• connected to a 2G or 3G network
• wifi only
• not compatible

www.gov.uk/alerts/how-alerts-work#compatible-devic...s