The PDA in this case would stand for Public Displays of Affection, like one person having their head in their partner's lap. The case has triggered a kerfuffle in India.

An excerpt from the NYT story:

MEERUT, India - On a crisp winter's afternoon in this small, unremarkable north Indian town, several couples - some married, some not - sat together on the benches of a well-groomed little park named after the country's most famous champion of nonviolence: Mohandas K. Gandhi.

In Meerut, the police cracked down on intimacy in Gandhi Park.
Soon came a band of stick-wielding police officers with television news cameras in tow. They yanked the couples by their necks, as though they were so many pesky cats, and slapped them around with their bare hands. The young women shielded their faces with their shawls. The men cowered from the cameras.

Apparently intended to clamp down on what the police consider indecent public displays of affection among unmarried couples, the nationally televised tableau in Gandhi Park backfired terribly. It set off a firestorm of criticism against police brutality, prompted at least one young unmarried pair to run away from home for a couple of days, and revealed a yawning divide on notions of social mores and individual rights in a tradition-bound swath of India where the younger generation is nudging for change.

"This is a basic infringement of our right to freedom," cried Vikas Garg, 21, a master's student in mass communications at the local Chaudhry Charan Singh University, a couple of days after the raid. "We are free to sit where we want."

Meerut police officials conceded that some officers overreacted. But they also defended their actions. Couples sat in "objectionable poses," said a defiant Mamta Gautam, a police officer accused in the beatings, including some with their heads in their partners' laps. Yes, Ms. Gautam went on, she had slapped those who tried to run away when the police asked for names and addresses. "If they were not doing anything illegal, why they wanted to run away?" the policewoman demanded in an interview. "I do not consider that what we did was wrong."

By the end of the week, as public outrage piled on, Ms. Gautam and three other police officers, including the city police superintendent, were suspended pending an internal investigation.

In a society where dating is frowned upon, public parks remain among the only places where couples can avail themselves of intimacy, from talking to necking and petting with abandon under the arms of a shady tree. Even if it is in broad daylight in a public park, romance before marriage remains taboo in small-town India, which is why the spectacle in Gandhi Park turned out to be such a big deal: to be outed in this way, on national television, is to bring terrible shame and recrimination on yourself and your family.