When you root an android device, you are tampering its technological protection, thus the legal bodies identifying it as circumvention of digital locks. The Digital Rights Management identifies this as a serious offence and holds different laws per country to defend rooting.
The copyright laws in India explicitly provide permission towards circumventing the Digital Rights Management (DRM). The provision for this was made in the form of an amendment to the existing laws in their Copyright (Amendment) Bill passed in 2012. The international bodies have been in constant fear about consequences of rooting as India holds the largest market for Android mobile phones, thus pressurizing for stricter laws over time.
Rooting is deemed as legal in Singapore. There are conditions attached to the process, however, that it might be performed with an intention that there will be no circumvention of the copyright and Android Rooting shall be done in order to protect the copyright. However, such conditions have never yet been tested in the court body yet.
In UK, there is the Copyright and Related Rights Regulations 2003 that identifies the need for DRM protection measures and deems them to be legal efforts. Copyright infringement attempts via Android Rooting are legally offensive, whereas, if performed for interoperability then are termed as legal.
In 2010, the Electronic Frontiers Australia announced in a press conference that it is unclear whether rooting is a matter of legal offence in Australia. However, there are existing laws that dictate the prevention of circumvention of the DRM. The Copyright Amendment Act of 2006 was responsible for strengthening the protection measures.
The Free Software Foundation group identifies that rooting must be deemed legal for any device. There is a European Directive 1999/44/CE that identifies replacement of one operating system with the other one, is not a matter of implication for voiding the warranty. This holds true till the manufacturer prove that modification caused the defect in the hardware.
There have been numerous efforts in the Canadian parliament in order to cause an amendment of the Copyright Acts so that they could assist more in prohibiting the possible tampering done on the digital locks. Whilst such efforts have been set aside, it would be worthwhile to mention that iPhone jailbreaking an iOS equivalent of Android Rooting is not terms as illegal.
The copyright laws in New Zealand allow the usage of the technical protection measures circumvention, so long as the usage of the same is done legally. When termed legally, it means non-copyright infringing purposes. The provision for this was made in Copyright Act of 1994.
The United States of America
Under the Digital Millennium Copyright Act, rooting of android devices is deemed as being illegal in the USA. however, there are exceptions via exemptions. The USA copyright office recognizes phones an exemption to this law. There has been an update to the exemption policies in the October 2012 whereas rooting of android smartphones still continues to be identified as being legal all across the USA.