"People are understandably fearful that their information or commentary could run afoul of the law, and so they err on the side of withholding it," says Benjamin Zawacki, a researcher on Southeast Asia for Amnesty International.
By defining lèse-majesté as a matter of national security, authorities have added teeth to the computer-crime law, which carries a maximum five-year jail term. Last month, a judge ordered the trial of a woman (who made an antiroyal public speech in 2008) to be closed to the public on grounds of national security. Her lawyer has contested the ruling.
Prime Minister Abhisit Vejjajiva, who took power in December after months of paralyzing protests, has said he wants to strike a balance between free speech and respect for the constitutional monarchy. Critics say he has failed and is unwilling to take on conservatives in his administration that are leading the crackdown.
Internet freedom fades
As in China, the Internet offers far more freedom than Thailand's mainstream media for discussing taboo topics. But that started to change in 2006, after the military ousted popular Prime Minister Thaksin Shinawatra.
As editor of Same Sky Books, a left-leaning periodical (online and print), Thanapol Eawsakul has often run afoul of Thai authorities.
In recent months, his site's Web boards have hosted lively debates on political upheaval and the role of the palace. Traffic on the website spiked last December when royalist protesters wearing yellow, the king's color, occupied Bangkok's airports in defiance of an elected government.
In January, authorities shut down the site, but it was moved to an overseas host server. Police have since questioned Mr. Thanapol and ordered him to delete allegedly offensive comments from the boards.