Yahoo IM blocks Trillian access

Beginning at about 6 p.m. on Wednesday (PST), Yahoo changed its instant messaging language to prevent third-party services, such as Trillian, from accessing its service. Like previous statements, the company said the block is meant as a pre-emptive measure against spammers from its Yahoo Messenger service.

"Spammers are being aided by entities that are abusing our systems, where they effortlessly gain knowledge of pathways and back-alley access to send spam," Yahoo spokeswoman Mary Osako said.

A Trillian spokesperson did not immediately return an email seeking comment.

Trillian software essentially folds in multiple IM clients under one interface. Although IM services from Yahoo, America Online and MSN cannot directly communicate, Trillian allows a user to chat with their buddies on all three systems under a common look and feel.

Yahoo's actions against Trillian are not new. The company has blocked Trillian in the past, including a handful of times last fall. Cerulean countered by implementing a work-around that soon restored access to Yahoo Messenger. Microsoft in October also shut out Trillian, saying it would have to strike an access agreement with the software giant to gain access to its users.

This time, however, Yahoo said it will continue changing its protocols to prevent clients such as Trillian from finding new ways to incorporate Yahoo. Again, the measure was cited by Yahoo as a way to prevent IM spam.

"By making frequent protocol changes, it is our expectation that spammers will be blocked from abusing our system to spam our users," Osako said.

IM spam, commonly referred to as "spim," has been flagged by experts as a growing problem. However, experts have also written off spim as a far cry from email spam, which has caused enormous headaches for consumers and businesses alike.

Market researcher The Yankee Group in April said that between 5 percent and 8 percent of all IM sent in corporations is spim. The study added that the percentage is unlikely to increase in the next year despite expected growth in new corporate IM users.

IM is different from email in that users can block strangers from communicating with them. Many IM clients have also added screening processes such as allowing communication only with people who appear on one's buddy list.

Regardless of whether IM spam is a growing and gathering problem, Yahoo's actions against Trillian illustrate the Web giant's efforts to further wall-off its proprietary IM network. The Big Three equivalent for Internet services have all watched their IM software proliferate thanks to their closed-door environments. Consumers must download multiple clients to chat with buddies in different IM services.

Blocking efforts such as Yahoo's have been controversial in the past. In 1999, when Microsoft launched MSN Messenger, the software allowed users to communicate directly with AOL Instant Messenger users. AOL, then the largest IM network, blocked MSN. The two companies proceeded to play a game of cat and mouse for months, until MSN finally said it would no longer access AOL to protect customer "security."

But when AOL acquired Time Warner in 2000, regulatory bodies and competitors brought back the MSN Messenger block as further evidence of the online giant's unfair practices. AOL eventually accepted regulatory provisions to rein in its IM business to gain approval of the merger.