For Americans: Tallinn visa run? (Moscow)

Hello Americans living in Moscow--

Writing to you from St. Petersburg. I am wondering if anyone has recently gone to Tallinn for a 3-month business/work visa. I had heard that this used to be possible until recently when the rules changed, and that it's no longer possible for Americans to leave Russia every three months and purchase a new visa.

Since this is all based on hearsay (as everything visa-related tends to be), I wanted to ask if anyone has actually tried this in the past month or so and been successful/failed.

Thanks very much.