DEAR JOYCE: After my manager saw me sending tweets to friends a few times this past week, she told me to end it or there would be consequences. I work in an office with a dozen other people and at least half tweet, but, so far as I know, they haven't been warned. Considering the fact that we often have to stay late without extra pay, I believe a great deal of leeway should be granted to employees who do small personal things at work. Have other readers complained about being told Twittering on the job is not allowed? -- K.N.

Not yet. But I did read an article ("Employers feel jitters as Twitter gets bigger") in the San Diego Union Tribune. It describes growing concerns about Twitter use in the workplace.

The time-loss issue is hardly new; it echoes the classic prohibitions against engaging in personal tasks of any kind --talking on the telephone, sending or reading e-mail, shopping or tracking news online, looking for a new job, playing online games, peeking at porn and so forth.

Employers worry that tweeting will spill the beans on proprietary information, violate company message control, engender security concerns and more. Companies are beginning to establish formal Twitter personnel policies.

What can you do about the Twitter scolding? Will a negotiating session with your manager adjust the time compensation for hours worked off-the-clock? How easily can you be replaced?

Two numbers of interest: Studies say that 40.5 percent of tweets fall into the "pointless babble" category, and that 5 percent of Twitter users account for 75 percent of all tweeting activity.