When you enter a street in game, you get an announcement of who all is on the street. If someone enters a street you are on, you also get an announcement. If you block a player, you do not see if they are on or have entered the street. However, they see that information about you.
To make this clearer and remove the blocker/blocked/blockee confusion, I'm going to use Kermit & Miss Piggy.
Kermit has blocked Miss Piggy after her numerous and annoying advances. He just does not want to deal with her anymore. He's out and about in Ur when he turns down Groddle Forrest Junction. Now, by chance, Miss Piggy is there collecting her coins when she gets the announcment that Kermit has entered the street. Kermit has no warning that she's there, so while he's walking down the street, she's surrounding herself with tempting meat and flowers and getting her bear ready to smother him with kisses. By the time Kermit gets down the street - it's too late, but if he'd gotten a warning, he could have easily and happily gone down another street. Which he does as soon as he sees her. Miss Piggy, of course, runs after him. When she gets there, she gets an announcement telling her that Kermit is there, but Kermit does not get a similar announcement telling him that Miss Piggy has entered. So he has no idea if it's safe to slow down to donate to Mab, milk a butterfly or, *gasp* nibble on another pig.
While stalking is an extreme example, if someone blocks another player, it's likely because they want to avoid them to a certain degree. Or, at least be warned that they may come in contact. It would be better, then, to have the announcements remain for the blocker (Kermit) and removed for the blockee (Miss Piggy). It might also be nice to have the location info removed from the blocker's (Kermit's) profile page if viewed by the blocked player (Miss Piggy).