Yes, the evidence is clear, the group People for the Ethical Treatment of Animals does indeed break laws when its agents go undercover. They have been documented as doing breaking and entering, not to mention copious amounts of theft and vandalism. Hopefully one day they'll get slapped with a federal RICO suit to put them out of business.
Yes, the group People for the Ethical Treatment of Animals breaks laws when its agents go undercover, because it is invading privacy, and even harassing and stalking people to go under cover. They should find other ways to make their points. It breaks laws and goes too far to lie to people in order to gain access under false pretenses. That is breaking and entering.
PETA has a right to protest the bad treatment of animals and the use of fur and such for vanity, but it does not have the right to go underground and terrorize people who think in a different way. Its actions are extreme in many cases and break the laws that are in place.
Even though I am strongly against them, PETA sending undercover agents to get information isn't an illegal activity, but I believe it is unethical. They do not break any laws by hiding their true motives when entering a business, but the actions they commit with their information often hurt business and disrupt the public.
When PETA representatives get a job under false pretenses, as long as they are fulfilling the job requirements and they don't sign any non-disclosure agreements, then they are completely within their rights to do so. People select their employers for a variety of reasons, all personal. If someone chooses to work for a company because they want to expose said company, that is their prerogative.
No, the group People for the Ethical Treatment of Animals does not break laws when it goes undercover, because there is nothing illegal about lying. As long as PETA does not trespass, or harass, or violate any other laws, it is not illegal to lie unless you are under oath. PETA is not breaking the law in most cases.