caller ID

Can't say much about why they didn't have caller id, but although Google was launched in Sept. 1999, it didn't really become operational until Dec. 2000. Since the movie was made Jan. 2000, a google search wouldn't have been feasible.

As noted by another user, Google wasn't really around when this movie was made. Plus, there were few resources to search for numbers at that time.

In addition, caller ID was still new (only a few phone companies offered it as far back as 1989-1990. Many smaller communities would potentially not even still have it as late as 1995 or so.

Even in places that offered it, it was a paid option, costing a few dollars each month. I remember it cost me $2.99 a month when I got it in late 1998. Many people opted not to pay for it. It was quite a few years before competition with cell phone companies and other wired companies (who came about after the telecommunications act of 1996) caused caller ID to become standard.

If that weren't enough, early caller ID systems often used different standards that didn't always work across all phone systems.

Finally, in the early days, cell phone numbers would not show up on it. They would show as "wireless caller", "unknown" or "unavailable". In addition, anyone with a brain and ill intent can enter the code to block their caller ID information before making a call, which would result in the message "blocked". While not common in 1999/2000 when this movie was made, it's also possible to spoof caller ID and hide your identity.

Believe me, before the year 2000 or so, it was a lot easier to make a victim out of someone in their own home. Even as late as the mid to late 1990s, cell phones were still sketchy and not everyone had one. The internet was still new and much of it was dial-up into the 2000's.