In the recent weeks I have received plenty of reports from mystery calls in Scotland (locator IO77sn):
A short overview:
SC0TID on 2016-11-11
B1TS/A on 2017-02-23
B1TS/B on 2017-02-23
S4BIT/A on 2017-02-27
S4BIT/B on 2017-03-01
He/she is obviously running a performant RX setup, generating a lot of spots.