Hackers have had a bonanza in April, May and June (so far). Nary has a day gone by without news of yet another major attack. Here’s a partial list of some of the most publicized hacks of the last 10 weeks:

RSA Security: On April 1, in a move akin to raiding Fort Knox, RSA’s Secure ID technology (one of the industry’s gold standards in security software) was hacked. RSA executives described the hack as “very sophisticated.” They characterized it as an advanced persistent threat (APT)-type targeted attack. It used a routine tactic – a phishing Email that contained an infected attachment that was triggered when opened.

Epsilon:  This Irving, TX –based company handles customer email messaging for over 150 firms, including large banks and retailers like Best Buy, JPMorgan Chase, Citigroup and L.L.Bean. In April, millions of consumers learned that Epsilon’s networks were breached when they received Emails from their banks and credit card companies informing them that the hack might have exposed their names and Email addresses to the hackers. Epsilon released a statement assuring consumers that only Email addresses and names were compromised and that no sensitive data was disclosed.

Revolving Door

In contrast to Apple’s stunning success, the first calendar quarter of 2011 was a revolving door for other Silicon Valley companies and executives. There were management shifts, shakeups and ousters at Advanced Micro Devices (AMD), Google, Hewlett-Packard (HP) and Microsoft. They were variously aimed at jumpstarting product momentum (AMD, Microsoft), polishing a tarnished image and placating stockholders (HP) and providing an orderly transition of power (Google).

You need a scorecard to keep up with all the comings and goings.

AMD’s board ousted chief executive Dirk Meyer in mid-January after only 18 months on the job. It then appointed Senior Vice President and CFO Thomas Seifert, as interim CEO while the search goes on for a permanent chief executive. Siefert continues as chief financial officer and says he does not want to be considered for the permanent CEO position. This is probably a smart move. AMD’s flamboyant co-founder Jerry Sanders spent 33 years as CEO (1969 to 2002), but everyone who’s followed has had a short tenure.

It’s hard to believe but the first quarter of 2011 is now a memory and we’re well into spring. The tone for the year in high technology was set in early January: fast, bold, aggressive action and sweeping management changes.

In the first four months of the year high tech vendors moved quickly and decisively to seize opportunities in established sectors (smart phones, virtualization, back-up and disaster recovery) and emerging markets (cloud computing, tablet devices and unified storage management). As 2011 unfolds, it’s apparent that high technology vendors are willing to shift strategies and shed executives in order to stay one step ahead of or keep pace with competitors. The competition is cutthroat and unrelenting. No vendor, no matter how dominant its market share, how pristine its balance sheet or how deep its order backlog and book to bill ratio dares relax or rest on its laurels for even a nanosecond.

Recaps of some of the year’s highlights thus far are very revealing.