This early Thursday, Venezuelan netizens started to report that Zello, the push-to-talk “walkie-talkie” app, had stopped functioning on mobile phones. Many Venezuelans have been using the app to organize and exchange information about the protests that have escalated rapidly over the last eighteen days now. Zello reported more than 15,000 local downloads in a single day last week. The blockage happened a day after President Maduro declared that the government was intercepting communications sent using Zello in order to monitor protesters.

On Twitter, Andrés Azpurua said:

Aparentemente se ha bloqueado Zello. es inaccesible de desde CANTV/movilnet, estamos investigando #BlackoutVE #freeinternetVE

— Andres E. Azpurua (@andresAzp) febrero 21, 2014

Apparently Zello is being blocked. It's unaccesible from CANTV/Movilnet, we're researching #BlackoutVE #freeinternetVE

The company asked users to report back using technical tools in order to understand the issue:

If you are in Venezuela and familiar with network diagnostics tools, please respond, we need your help to understand the block applied.

— Zello Inc (@Zello) febrero 21, 2014

Loris Santamaria, a consultant in network infrastructure services, did a traceroute and reported:

Some traces, first two done using ADSL provider Cantv. Last one is via mobile provider Movistar @Zello pic.twitter.com/CS8NehIUmb

— Loris Santamaria (@lorissantamaria) febrero 21, 2014

Zello is not blocked on Movistar 3G network, however because that is a metered service most were using zello via Cantv, thru wi-fi @Zello

— Loris Santamaria (@lorissantamaria) febrero 21, 2014

On Thursday night, the company declared to Associated Press that the origin of the blockage was Venezuela's state-run telecommunications company, CANTV, which covers over 80% of the telecom market in the country. Later, they developed a new version, hoping that it would prove useful to circumvent the blockage:

Android users in Venezuela, who cannot access the app. Please try this version and report back results http://t.co/e5XZKYusOw

— Zello Inc (@Zello) febrero 22, 2014

Meanwhile, TunnelBear, the VPN company, who has been providing unlimited free service Venezuelans for several days, tweeted to Zello their approach:

@fbajak @Zello TunnelBear should unblock Zello for iPhone and Android. We are currently providing free service to #Venezuela #censura

— TunnelBear (@theTunnelBear) febrero 21, 2014

Surveillance and censorship are increasingly serious concerns for all Internet and mobile phone users in Venezuela. Yesterday, the Inter-American Commission on Human Rights issued a statement pressing upon the need for free access to information:

La Comisión Interamericana reitera a las autoridades venezolanas que es indispensable que en una sociedad democrática existan garantías suficientes para asegurar que la población tenga acceso al pluralismo y la diversidad informativa, especialmente en relación con temas de interés público y el acontecer nacional.

The Inter-American Commission reiterates to Venezuelan authorities that it is indispensable in a democratic society to ensure sufficient guarantees assuring that the population has access to pluralistic and diverse information, especially in relationship to matters of public and national interest.