Last week, numerous data from Steam users were exposed. Now there is an explanation of what happened.
A major DDoS attack
For a moment, it looked like a huge disaster. Last week, many Steam users were surprised when they suddenly had different language settings on the platform. But that was just the harmless part. Many of you were logged in with strangers’ profiles from other players, had access to their purchase lists and even some data, such as the last digits of their credit card. Really sensitive data, such as passwords or addresses, were never publicly available, it has been emphasized repeatedly.
The reason for this problem was a DDoS attack, which is an artificially generated overload of the servers, where it was flooded with numerous requests until the system came to a halt. The corresponding error then occurred due to a countermeasure to contain the attack – user requests that were in the cache were made accessible to other users.

It is also interesting to know that during the Steam Sale, access to the shop increases by nearly 2000% compared to normal usage. Although this is of course not reliable data on sales, it seems that the Steam Sale is profitable for Valve again this year.
Valve wants to find out exactly whose data was accessible and will contact the respective users to advise them on what steps to take next.
Mein-MMO states: All in all, the problem seems to have had no major consequences, aside from a significant loss of reputation for Valve. Whether the company will succeed in regaining the trust of the users – or whether the entire matter will simply fade away (due to a lack of alternatives) – remains to be seen.