[This hasn't been posted in the Blizzard thread as it's a new problem occurring from 18/4/17]
Since the 18th, Virgin Media players on Overwatch have been randomly disconnecting from competitive matches. Players playing in groups have noted that all players with Virgin Media are booted from the game at the same time, while other players are unaffected. E.g.:
As you can see, Blizzard customer services on both Twitter and their own website are insistent that the problem is on Virgin Media's end. Here's the text from a support ticket:
"Even though the timing suggests that this is an issue with the recent patch, the fact that patch 2.10 has released is actually coincidental - this is actually a problem with Virgin Media's network, and we have received a lot of reports from other customers of this ISP reporting as such.
So, as much as we would like to be able to provide help, I'm afraid this is something your ISP has to solve for you. Make sure to contact them as soon as possible."
Assistance would be appreciated because the game is unplayable with this issue in place - we risk being banned for disconnecting during competitive games.
How long have those problems been happening though? My friend and I have been playing Overwatch nearly every day for a year now, we've had our share of connection issues but we've never been disconnected at the same time until two nights ago. Now we've had something like 4 in our last 7 games. All the sources quoted the OP are from the last 24 hours too.
It seems that they've changed something in the last few days.