For what it's worth, backdoors have been discovered in Ericsson switches, see [1], it's fascinating reading. It's unclear who put them there. Wikipedia [2] alle

For what it's worth, backdoors have been discovered in Ericsson switches, see [1], it's fascinating reading. It's unclear who put them there. Wikipedia [2] alleges that the US embassy in Athens was behind the telephone intercepts. Naturally, Wikipedia is n o t a reliable source in such matters. I used to work in telecoms myself about 20 years ago, and at least at the time, much of infrastructure was insanely insecure -- I could have backdoored much of the internet's backbone as a lone programmer had I wanted to: our software was used by most big telcos. Not once was our code audited (at least openly). I very much hope that security is taken more seriously now. [1] V. Prevelakis, D. Spinellis, The Athens Affair. https://web.archive.org/web/20070704193410/http://www.spectrum.ieee.org/jul07/5280 https://web.archive.org/web/20070704193410/http://www.spectr... The pdf is also available through Spinellis' Google Scholar page. [2] https://en.wikipedia.org/wiki/Greek_wiretapping_case_2004%E2%80%9305 https://en.wikipedia.org/wiki/Greek_wiretapping_case_2004%E2...