April is transportation month at Global Voices, which is why it is only prudent to refer once again  to the public transportation system in Mexico's capital city.
The Metro is basically the mode of transportation that mobilizes the most citizens in Mexico City, with an estimated influx of 435,440,200 passengers between October and December 2013, according to official figures  [es] from last year. With such a high demand, it is natural that all sorts of users will express themselves on blogs and social networks.
For example, on the Íconos del Metro  [es] blog, the author has taken on the task of sharing images of every station, as well as an explanation of them, for reasons he summarizes as follows:
Como parte de un proyecto aparte, realicé un par de íconos del metro en formato vectorial, deseaba ponerlos a disposición de todos en la Wikipedia, pero resulta que el Sistema de Transporte Colectivo tiene los derechos reservados sobre la iconografía de las estaciones del Metro de la Ciudad de México, y prohíbe la inclusión de estos logotipos en la enciclopedia en línea. Así pues se los comparto en este blog.
As part of a separate project, I made a couple of metro signs in a vector format. I wanted to make them available to everyone on Wikipedia, but it turns out that the Public Transportation System has reserved all rights to iconography in Mexico City's Metro stations and prohibits the inclusion of these logos in the online encyclopedia, so I'm sharing them on this blog.
On Twitter, user D G Miramontes (@zombicosmico) uses hashtag #miamigoelmetro  [es] [my friend the metro] to spread her messages about everyday experiences on this mode of transportation:
— D G Miramontes (@zombicosmico) January 12, 2013 
My friend the Metro saving the dog
Other users took this opportunity to publish their complaints, as is the case for Dana A. Salas (@salasdana) who expressed her feelings about the presence of street vendors or “vagoneros” (“roaming vendors”) in the Metro cars:
Según en el #MetroDF  del s.XXI que nos ofrecieron ya no iba haber vendedores ambulantes. En mi trayecto de hoy conté al menos a siete.
— Dana A. Salas (@salasdana) April 10, 2014 
According to the DF Metro of the 21st century that were offered to us, there were not going to be any more roaming vendors. On my commute today, I counted at least seven.
Daniel Rosas (@DanielRosasH) spoke out in the same vein:
La burla en el Metro del #DF  continúa, los vagoneros desfilan uno tras otro en mayor número y los trenes tardan en una estación 5 mins o +
— DANIEL ROSAS (@DanielRosasH) March 24, 2014 
Mockery in the DF Metro continues, train vendors parade one after the other in greater numbers and trains are stopped at one station for 5 minutes or more.
The biggest complaint about the Metro, however, is one that has to do with the great work done by the administration of the Head of Government, Marcelo Ebrard (known among other things for his online interactions with citizens ): a whole new metro line that has had to close down a few months after his inauguration, given the litany of irregularities (financial or legal) and technical failures that it has presented. The issue was summarized by journalist Joaquín López-Dóriga  [es]:
Nunca nadie pudo imaginar que la Línea 12 del Metro, la obra emblemática de Marcelo Ebrard, fuera a desembocar en el conflicto técnico, económico y político que ha escalado. Cuando aquel 30 de octubre de 2012, el entonces jefe de Gobierno del Distrito Federal cortó el listón acompañado del presidente Felipe Calderón, todo eran sonrisas y proyectos.
No one could ever imagine that Metro Line 12, Marcelo Ebrard's iconic work, would end up in the technical, economic, and political conflict that has escalated. When the then Head of the Federal District cut the ribbon on October 30, 2012, accompanied by President Felipe Calderón, it was all smiles and projects.
The journalist in question compared this local government public work to one of the flagship works of the federal government (the Estela de Luz , which was delivered extemporaneously and at an extra cost):
Catorce meses después comenzó la pesadilla con una Línea 12 que se desdoró en medio de la reiterada incapacidad gubernamental de gestión, de gerencia de obras pública, como en la Estela de Luz, la sede del Senado, de un tramo fundamental del emisor central y los segundos pisos, por citar algunos. La Línea 12, una obra fundamental que mejoró sustancialmente la calidad de vida de medio millón de personas al día, se las empeoró en menos de 24 horas, el pasado 11 de marzo, cuando se suspendió el servicio y corrida en 11 de sus veinte estaciones, once de sus 21 kilómetros.
Fourteen months later, the nightmare with Line 12 started, which was tarnished amidst the reiterated government inability to manage, to manage public works like the Estela de Luz, the Senate seat, a key stretch of the central transmitter and the second floors, to name a few. Line 12, a fundamental work that improved the quality of life substantially for half a million people per day, worsened in less than 24 hours on March 11, when the service and route in 11 of its twenty stations and eleven of its 21 kilometers were suspended.
On Twitter, user Jorge (@BladeMithology ) expressed himself about the ignominious closure of Mexico City's Metro Line 12:
— JORGE (@BladeMithology) April 10, 2014 
And the more you scratch Line12 the more it smells of corruption… Fail
So thus, with a look at public transportation in the Mexican capital, you can get a good idea of the challenges that citizens struggle with on a daily basis.